1772 Is a Centered Heptagonal Number!

Today’s Puzzle:

It’s early in 2024, so here’s a Factor Fits puzzle utilizing the factors of 20 and 24. Give it a try! There is only one solution.

Factors of 1772:

This is my 1772nd post. What are the factors of 1772?

  • 1772 is a composite number.
  • Prime factorization: 1772 = 2 × 2 × 443, which can be written 1772 = 2² × 443.
  • 1772 has at least one exponent greater than 1 in its prime factorization so √1772 can be simplified. Taking the factor pair from the factor pair table below with the largest square number factor, we get √1772 = (√4)(√443) = 2√443.
  • The exponents in the prime factorization are 2 and 1. Adding one to each exponent and multiplying we get (2 + 1)(1 + 1) = 3 × 2 = 6. Therefore 1772 has exactly 6 factors.
  • The factors of 1772 are outlined with their factor pair partners in the graphic below.

1772 is a Centered Heptagonal Number:

1772 is one more than 7 times the 22nd triangular number. For all previous centered heptagonal numbers about which I’ve written, I only mentioned their inclusion in this set of numbers. This time, I was determined to produce a graphic of the number. I used Desmos and Excel to determine all 1772 points in the graphic. It was a little time-consuming, but I got it done!

The points of the first heptagon were (1, 0), (cos2π/7, sin2π/7), (cos4π/7, sin4π/7), (cos6π/7, sin6π/7), (cos8π/7, sin8π/7), (cos10π/7, sin10π/7), (cos12π/7, sin12π/7). Here is an example of what was involved in completing one side of the other heptagons: Suppose I wanted to find five points on the line connecting (a,c) and (b,d). The five points would be
((4a+0b)/4, (4c+0d)/4), or simply (a, c),
((3a+1b)/4, (3c+1d)/4),
((2a+2b)/4, (2c+2d)/4), or simply ((a+b)/2, (c+d)/2), the midpoint,
((1a+3b)/4, (1c+3d)/4),
((0a+4b)/4, (0c+4d)/4), or simply (b, d).

I used Excel to calculate those numbers and then copied and pasted them into Desmos which graphed them beautifully. Each round took me less than ten minutes to complete. Here is the finished product:

More About the Number 1772:

1772 is the difference of two squares:
444² – 442² = 1772.

1772 is palindrome 24042 in base 5. Why?
Because 2(5⁴)+4(5³)+0(5²)+4(5¹)+2(5º) = 1772.

Facts and Factors for the Year 2024

A Countdown to 2024:

2024 Countdown

make science GIFs like this at MakeaGif
Here are some other countdowns:

What Kind of Factors Will the Year 2024 Bring Us?

Here’s a factor cake to celebrate 2024’s arrival:

And its factor pairs are outlined on this chart:

The sum of all the factors of a number (excluding itself) determines if a number is deficient, perfect, or abundant. Which of those describes 2024?

Powerful Facts About the Number 2024:

2³ + 3³ + 4³ + 5³ + 6³ + 7³ + 8³ + 9³ = 2024, as illustrated below

2¹º + 10³ =2024.

2024 is the sum of eleven consecutive even square numbers:

2024 is the difference of two squares in FOUR different ways:

507² – 505² = 2024,
255² – 251² = 2024,
57² – 35² = 2024, and
45² – 1² = 2024.

One of those four equations brings us to…

Today’s Puzzle and Some Other 2024-Themed Puzzles:

Here are some other 2024-themed puzzles:

2024 in Pythagorean Triple Triangles

2024 is a leg in quite a few Pythagorean triple triangles. Here are a few:

I didn’t even include all the triangles listed on the left in the illustration because some of the points were too close together with the scale I used in Desmos.

I also didn’t include
2024² + 512070² = 512074 or
2024² + 128010² = 128026
because those triangles would have made the scale even worse.

There are more triangles, but I think this is a good enough representation.

Here’s a more complete list:

2024 is NOT the hypotenuse of any Pythagorean triple because none of its prime factors leave a remainder of 1 when divided by 4.

2024 in Pascal’s Triangle:

2024 is in the 24th row of Pascal’s triangle. Click on the image to see the numbers in the image better.

Since it is in the third column of that 24th row, 2024 is a Tetrahedral number. That means it is the sum of the first 22 triangular numbers. That fact can be illustrated as I have here in this vertically rotating Desmos 3D image. Go ahead and click on the image below to see this tetrahedron rotating more horizontally. Also, notice that I made the image with 2024 quarter-unit spheres.

As I stated before, the image is made from the first 22 triangular numbers stacked on top of each other. The sum of the first 22 triangular numbers is given below:

This tetrahedral number can also be expressed mathematically in this way:

This way:

The second way listed here:

Or this way:

2024 Consecutive Number Sums

2024 is the sum of consecutive counting numbers in three different ways:

2024 is the sum of consecutive odd numbers in four different ways: (It’s because 2024 is the difference of two squares in four different ways.)

2024 is the sum of consecutive even numbers:

8 consecutive even numbers:
246+248+250+252+254+256+258+260=2024.

11 consecutive even numbers:
174+176+178+180+182+184+186+188+190
+192+194=2024.

23 consecutive even numbers:
66+68+70+72+74+76+78+80+82+84+86+88+90+92
+94+96+98+100+102+104+106+108+110 = 2024.

2024 Magic Sums

2-0+2-4 = 0, so 2024 is divisible by 11. That means it is the magic sum of an 11 × 11 Magic Square. Here is one way that Magic Square can be completed. I followed the directions given in this post. You can see the 11 consecutive numbers listed above along the lower left to upper right diagonal.

If you would like to try completing the magic square yourself, here’s an Excel template that will automatically add the sums while you enter the numbers: 1766-1772 and 2024 Magic Squares

2024 is divisible by 8 but not by 16, so it is the Magic Sum of a 16 × 16 Magic Square. Here are two examples:

For this first one, I wrote the numbers from -1 to 14 across the top of the puzzle and continued in like manner. After the numbers were in place, I started flipping diagonals. How many diagonals did I flip?  34: The sixteen green diagonals, the sixteen blue diagonals, the pink diagonal, and the brown diagonal.

Here is how it looked when I finished:

For this second one, I wrote the numbers from -1 to 14 in the first 4 × 4 square, the numbers from 15 to 30 in the second 4 × 4 square, etc. Then I began flipping diagonals.

The Excel sheet, 1766-1772 and 2024 Magic Squares, also includes a template that will allow you to complete just a 4 × 4 magic square in the lower right corner for the numbers from -1 to 14. The whole 16 × 16 magic square will populate if you just complete that 4 × 4 magic square! But there’s a template if you want to do the whole thing from scratch as well.

More About the Number 2024:

Because 2024 is the sum of the 16 numbers from 119 to 134,
and 16 is even, it follows that
134²-133²+132²-131²+130²-129²+128²-127²+126²
-125²+124²-123²+122²-121²+120²-119²=2024.

Here is a way to make 2024 using only the digits 2, 0, 2, and 4:

(2+0+2+4)×
(2+0+2+4-(2+0)/2+4)×
(((2+0+2+4)×(-(2+0)/2+4))-(2+0+2)/4) = 2024.

The tan²(88.7266556386°) ≈ 2024, so it is the solution to this next problem:

 

1771 Pascal’s Triangle and the Twelve Days of Christmas

A Twelve Days of Christmas Puzzle with Triangular and Tetrahedral Numbers:

I wanted a copy of Pascal’s triangle with 14 rows. I couldn’t find one, so I made my own. To fill in the missing number in a cell, simply write the sum of the two numbers above it. I would suggest filling it in together as a class so that they can see how it is done without actually having to write in all the numbers themselves. The biggest missing sum is 364.

After filling that puzzle in together as a class, I would give students this next copy of Pascal’s triangle to use.

There are many patterns in Pascal’s triangle. It can be fun to color them with that in mind. I would caution students to color lightly so that they can still read the numbers afterward. How did I color this one? If the number in a cell is not divisible by the row number, I colored it green. Of course, all the 1’s were colored green. If all the other numbers in the row were divisible by the row number, I colored all of them red. If only some of them were, I colored them yellow. Notice that the row number of every row that is red is a prime number. Composite row numbers will always have at least one entry that is not divisible by the row number.

I divided each of the numbers in this next one by 3, noted the remainder, and colored them accordingly:

  • remainder 0 – red
  • remainder 1 – green
  • remainder 2 – yellow

1771 is a Tetrahedral Number:

364 = 12·13·14/6. That means it is the 12th tetrahedral number.
If my true love gave me all the gifts listed in the Twelve Days of Christmas song, it would be a total of 364 gifts. Since I don’t have use for all those birds, if I returned one gift a day, it would take me 364 days to return them all. That’s one day less than an entire year!

1771 = 21·22·23/6. That means it is the 21st tetrahedral number.
If there were 21 days of Christmas, and the pattern given in the song held, my true love would give me 1771 gifts. Yikes, I’ll need a bigger house or maybe a bird sanctuary!

Here is one-half of the 23rd row in Pascal’s triangle showing the number 1771:

I’ve also been thinking about the next tetrahedral number after 1771 because the year, 2024, has almost arrived. Note to my true love: I don’t need or want 2024 gifts, please!

Factors of 1771:

1771 is a palindrome with an even number of digits, so 1771 is divisible by eleven.

  • 1771 is a composite number.
  • Prime factorization: 1771 = 7 × 11 × 23.
  • 1771 has no exponents greater than 1 in its prime factorization, so √1771 cannot be simplified.
  • The exponents in the prime factorization are 1, 1, and 1. Adding one to each exponent and multiplying we get (1 + 1)(1 + 1)(1 + 1) = 2 × 2 × 2 = 8. Therefore 1771 has exactly 8 factors.
  • The factors of 1771 are outlined with their factor pair partners in the graphic below.

More About the Number 1771:

1771 is the difference of two squares in four ways:

886² – 885² = 1771,
130² – 123² = 1771,
86² – 75² = 1771, and
50² – 27² = 1771.

It is easy to see that 1771 is a palindrome in base 10, but it is also a palindrome in some other bases:
It’s 4H4 in base 19 because 4(19²)+17(19)+4(1)=1771,
232 in base 29 because 2(29²)+3(29)+2(1)
1T1 in base 30 because 1(30²)+29(30)+1(1)=1771, and
NN in base 76 because 23(76)+23(1).

1770 This Christmas, Don’t Let the Taxman Get Most of Your Cash!

Today’s Puzzle:

1770 = 30 · 59.
1770 = (60 · 59)/2.

That means 1770 is a triangular number. If we have 59 envelopes numbered 1 to 59, and each envelope contained the amount of money on the outside of the envelope, we would have $1770 in cash at stake. In this game, the TAXMAN wants to take as much money as he can get, but you control how much he can take: Can you allow him to get as little as possible? 

You can play Taxman easily with these printable Taxman “envelopes” and Taxman Scoring Calculator because each “envelope” lists all the factors of the envelope number. Your first selection should be the biggest prime number on the board because then the only envelope the taxman can get on that turn is the 1 envelope. The Taxman must be able to take at least one envelope on every turn. Try to make it so he can only get one or at most two envelopes on each turn. When it is no longer possible for you to take an envelope that allows the Taxman to take at least one envelope, too, the taxman gets ALL the rest of the envelopes. You win if you can keep more than half of your cash. Good luck!

Factors of 1770:

  • 1770 is a composite number.
  • Prime factorization: 1770 = 2 × 3 × 5 × 59.
  • 1770 has no exponents greater than 1 in its prime factorization, so √1770 cannot be simplified.
  • The exponents in the prime factorization are 1, 1, 1, and 1. Adding one to each exponent and multiplying we get (1 + 1)(1 + 1)(1 + 1)(1 + 1) = 2 × 2 × 2 × 2 = 16. Therefore 1770 has exactly 16 factors.
  • The factors of 1770 are outlined with their factor pair partners in the graphic below.

More About the Number 1770:

As mentioned earlier 1770 is the 59th triangular number because 59(60)/2 = 1770.

1770 is also the 30th hexagonal number because 30(2·30-1) = 1770. (Every hexagonal number is also a triangular number.)

I’ve made images of hexagonal numbers before, but this time I wanted to make one using this hexagon template:

1770 is the hypotenuse of a Pythagorean triple:
1062-1416-1770, which is (3-4-5) times 354.

1770 is repdigit, UU, in base 58 because
30(58) + 30(1) = 30(58 + 1) = 30(59) = 1770.

1769 I Want a Hip Hypotenuse for Christmaths

Today’s Puzzle:

Why do I want a hip hypotenuse for Christmaths?

Many have heard the equation a² + b² = c² to help find the hypotenuse of a right triangle when given two legs. What do you do if you are given the hypotenuse and a leg instead of two legs? You use b² = c² – a².

Sometimes finding squares and taking square roots is not too difficult:

  • x = √(29²-21²)                              x = √(61² – 11²)
  • x = √(841-441)                           x = √(3721 – 121)
  • x = √400                                         x = √3600
  • x = 20                                              x = 60

Other times it can be more challenging:

  • x = √(177² – 48²)
  • x = √(31329 – 2304)
  • x = √29025
  • x ≈ 170.37, that’s irrational and not in the simplest form. Finding the factors of 29025, so its square root can be simplified, is going to be a pain!

Try this instead:

  • x = √(177² – 48²) That’s the difference of two squares, so it can be factored!
  • x = √((177 – 48)(177 + 48))
  • x = √(129 · 225) I love that I have two factors instead of one big number! And in this case, one of them is a perfect square! 225 = 15².
  • x = √(3 · 43 · 15²)
  • x = 15√129.

Most people learn the Pythagorean theorem before they learn how to factor the difference of two squares, but then they never apply it to the Pythagorean theorem. Once you know both concepts, factor whenever you can!

A Math Parody of the Song, “I Want a Hippopotamus for Christmas”

On Thanksgiving, my son gave me an early Christmas present: a t-shirt that had a right triangle with a hippopotamus sprawled over the hypotenuse. The shirt had the words, “I want a hippopotenus for Christmath” at the bottom.

Somebody suggested that I sing it.

I looked for a mathematical version of I Want a Hippopotamus for Christmas and couldn’t find one, so I made my own. I decided I liked “hip hypotenuse” better than “hippopotenuse” and that the British “maths” sounded better than the American “math.” Then I recorded it. If I had more time, I would have waited until I didn’t have a cold and would have worked on my timing a bit more. Since I wanted it to be ready to present on a certain day at school, I just went with it as is. I hope you enjoy it.

I shared it with my family. Here’s how one of my sons responded:

Well, some moms have made negative comments about their kid’s ability to learn some math concepts. Indeed, I didn’t.

I already had been thinking about reworking some of the lyrics, making the first half of the song about the Pythagorean theorem and the second half about Trigonometry. I’ll re-record it sometime, but here are the lyrics I’ll use for the revised version:

I want a hip hypotenuse for Christmaths.
Only a hip hypotenuse will do.
I don’t want a doll, no dinky tinker toy;
I want a hip hypotenuse to play with and enjoy!

I want a hip hypotenuse for Christmaths.
I don’t think Santa Claus will mind, do you?
He won’t have to use those squares to find the last side, too.
Just the difference times the sum. That’s an easy root to do.

I can see me now on Christmaths morning calculating squares.
Oh, what joy and what surprise
When I open up my eyes
To see that hip hypotenuse given there.

I want a hip hypotenuse for Christmaths,
Only a hip hypotenuse will do.
No crocodiles, eating more or lesses.
I only like hip hypotenuses.
And hip hypotenuses like me, too.

I want a hip hypotenuse for Christmaths.
A hip hypotenuse is all I want.
Mom says triangles are often right, for them
Teacher taught a theorem that is Pythagorean.

I want a hip hypotenuse for Christmaths,
The kind that’s used in trigonometry.
The sine of an angle is its opposite side
Over the hip hypotenuse. Make sure it’s simplified!

I can see me now on Christmaths solving triangles downstairs.
With the laws of sines and cosines.
Each time(?!) I must choose
When there’s no hypotenuse anywhere.

I WANT a hip hypotenuse for Christmaths,
Only a hip hypotenuse will do.
No crocodiles, eating more or lesses.
I only like hip hypotenuses.
And hip hypotenuses like me, too.

I hope my song made you laugh. For more laughs, check out this Statistics Saturday post at Another Blog, Meanwhile. He lists several humouous hippopotamus-related unwise Christmas gifts.

Factors of 1769:

This is my 1769th post. What are the factors of 1769?

  • 1769 is a composite number.
  • Prime factorization: 1769 = 29 × 61.
  • 1769 has no exponents greater than 1 in its prime factorization, so √1769 cannot be simplified.
  • The exponents in the prime factorization are 1 and 1. Adding one to each exponent and multiplying we get (1 + 1)(1 + 1) = 2 × 2 = 4. Therefore 1769 has exactly 4 factors.
  • The factors of 1769 are outlined with their factor pair partners in the graphic below.

More About the Number 1769:

1769 is the sum of two squares in two different ways:

40² + 13² = 1769, and
37² + 20² = 1769.

1769 is the hypotenuse of FOUR Pythagorean triples:
319-1740-1769, which is (11-60-61) times 29,
969-1480-1769, calculated from 37² – 20², 2(37)(20), 37² + 20²,
1040-1431-1769, calculated from 2(40)(13), 40² – 13², 40² + 13²,
1220-1281-1769, which is (20-21-29) times 61.

Did you notice that 20-21-29 and 11-60-61 were the two triangles used in today’s puzzle? It would not have been so easy if I had used 319-1740-1769 and 1220-1281-1769 instead!

1769 is a palindrome in some other bases:
It’s 585 in base 18,
1I1 in base 34, and
TT in base 60.

1768 A Polygonal Christmas Tree on Desmos

I created this polygonal Christmas tree with a polygonal star on Desmos, and it looks like it is living and breathing to me!

Later I saw this Christmas tree post and decided to share it here:

Today’s Puzzle:

Can you find the factors that belong on this Christmas factor tree for 1768?

Factors of 1768:

  • 1768 is a composite number.
  • Prime factorization: 1768 = 2 × 2 × 2 × 13 × 17, which can be written 1768 = 2³ × 13 × 17.
  • 1768 has at least one exponent greater than 1 in its prime factorization so √1768 can be simplified. Taking the factor pair from the factor pair table below with the largest square number factor, we get √1768 = (√4)(√442) = 2√442.
  • The exponents in the prime factorization are 3,1 and 1. Adding one to each exponent and multiplying we get (3 + 1)(1 + 1) (1 + 1) = 4 × 2 × 2 = 16. Therefore 1768 has exactly 16 factors.
  • The factors of 1768 are outlined with their factor pair partners in the graphic below.

More About the Number 1768:

1768 is the sum of two squares in two different ways:
38² + 18² = 1768, and
42² + 2² = 1768.

1768 is the hypotenuse of FOUR Pythagorean triples:
168-1760-1768, calculated from 2(42)(2), 42² – 2², 42² + 2²,
680-1632-1768, which is 136 times (5-12-13),
832-1560-1768, which is 104 times (8-15-17),
1120-1368-1768, calculated from 38² – 18², 2(38)(18), 38² + 18².

The first triple is also 8 times (21-220-221), and
the last triple is also 8 times (140-171-221).

1768 looks interesting in some bases you probably would never care about:

It’s 404 in base 21 because 4(21²) + 0(21) + 1(1) = 1768.
It’s 1Q1 in base 31,
YY in base 51, and
QQ in base 67.

Can you solve for Q and Y?

1767 My 10-Year Blogiversary

Today’s Puzzle:

Ten years ago today, I published my first blog post. I decided to commemorate the day by making a Factor Fits puzzle with not one, but two, tens in it.

Factors of 1767:

This is my 1767th post. What are the factors of 1767?

  • 1767 is a composite number.
  • Prime factorization: 1767 = 3 × 19 × 31.
  • 1767 has no exponents greater than 1 in its prime factorization, so √1767 cannot be simplified.
  • The exponents in the prime factorization are 1, 1, and 1. Adding one to each exponent and multiplying we get (1 + 1)(1 + 1)(1 + 1) = 2 × 2 × 2 = 8. Therefore 1767 has exactly 8 factors.
  • The factors of 1767 are outlined with their factor pair partners in the graphic below.

More About the Number 1767:

1767 is the difference of two squares in four different ways:
884² – 883² = 1767,
296² – 293² = 1767,
56² – 37² = 1767, and
44² – 13² = 1767.

1767 is the sum of consecutive numbers in several different ways. In each case, I’ve highlighted the numbers in the middle of the sum. What do you notice about those numbers?

1767 is the sum of two consecutive numbers:
883 + 884 = 1767.

It is the sum of three consecutive numbers:
588 + 589 +590 = 1767.

1767 is the sum of six consecutive numbers:
292 + 293 + 294 + 295 + 296 + 297 = 1767

It is the sum of 19 consecutive numbers:
84 + 85 + 86 + 87 + 88 + 89 + 90 + 91 + 92 + 93 + 94 + 95 + 96 + 97 + 98 + 99+ 100 + 101 + 102 = 1767.

1767 is the sum of 31 consecutive numbers:
42 + 43 + 44 + 45 + 46 + 47 + 48 + 49 + 50 + 51 + 52 + 53 + 54 + 55 + 56 + 57 + 58 + 59 + 60 + 61 + 62 + 63 + 64 + 65 + 66 + 67 + 68 + 69 + 70 + 71 + 72 = 1767.

It is the sum of 38 consecutive numbers:
28 + 29 + 30 + 31 + 32 + 33 + 34 + 35 + 36 + 37 + 38 + 39 + 40 + 41 + 42 + 43 + 44 + 45 + 46 + 47 + 48 + 49 + 50 + 51 + 52 + 53 + 54 + 55 + 56 + 57 + 58 + 59 + 60 + 61 + 62 + 63 + 64 + 65 = 1767

AND 1767 is the sum of 57 consecutive numbers!
3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 + 11 + 12 + 13 + 14 + 15 + 16 + 17 + 18 + 19 + 20 + 21 + 22 + 23 + 24 + 25 + 26 + 27 + 28 + 29 + 30 + 31 + 32 + 33 + 34 + 35 + 36 + 37 + 38 + 39 + 40 + 41 + 42 + 43 + 44 + 45 + 46 + 47 + 48 + 49 + 50 + 51 + 52 + 53 + 54 + 55 + 56 + 57 + 58 + 59 = 1767.

1767 is repdigit, VV, in base 56 because
V(56) + V(1) = 1767. What does V equal? You can figure it out!

V(56) + V(1) = 1767.
V(57) = 1767.
V = 1767/57.

The 168th Playful Math Education Blog Carnival

A Couple of Carnival Puzzles for You to Solve:

Puzzle one: There are 168 prime numbers less than 1000, and four of them are consecutive primes that add up to 168. Can you figure out what those four prime numbers are? Hint: The average of the four prime numbers will be 168÷4.

Puzzle two: How many pips (dots) are on this regular set of 28 dominoes?

I’ve grouped the dominoes into groups with six dots. How many groups of six are there? Multiply six by the number of groups and you will know the number of dots. You can also count them by using this cool triangular display from Wikipedia.

Five Amazing Facts about the Number 168:

168 isn’t perfect, but it is the product of the first two perfect numbers, 6 and 28.

Most of us recognize that 168 is one less than a perfect square, so 13² – 1² = 168, but did you know that 168 is also the difference of two squares in three other ways?
43² – 41² = 23² – 19² = 17² – 11² = 168.

Here’s another square way to make 168:
18² – 17² + 16² – 15² + 14² – 13² + 12² – 11² + 10² – 9² + 8² – 7² + 6² – 5² + 4² – 3² = 168.

2¹⁶⁸ = 374144419156711147060143317175368453031918731001856. Look it over. You won’t see a “2” anywhere in that 50-digit number. 2¹⁶⁸ is the largest known power of 2 not to contain each of the 10 digits at least once.

168 is a repdigit in several other bases:
168₁₀ = CC₁₃ = 88₂₀ =77₂₃ = 66₂₇ = 44₄₁ = 33₅₅ = 22₈₃ = 11₁₆₇ = 168₁₀.

More Domino Fun:

The DewWool blog has made ten free domino worksheets for kindergarten and first-grade students to practice addition.

You can also use a double nine set of dominoes to solve an algebra problem:

And what about using dominoes to add fractions?

Autumn Math:

If your town has a scarecrow trail, you can add some learning while you take the kids around. They can learn about many subjects including mathematics as they do the activities suggested in this blog post by Curious Kids 101.

Apples have several lessons inside of them. AdamPetersonEducation suggests using apple seeds as manipulatives in Apple Activities in the Classroom.

Math Story Books:

Writer’s Rumpus’s post about a brand-new picture book, Smarty Ants, by Corey Rosen Schwartz and Kirsti Call, illustrated by Erin Taylor. The blog post includes pictures that clearly show some of the math involved in what looks like a delightful story. There’s even a song for your students to enjoy.

Way Past Embarrassed by Hailey Adelman is a picture book that will help students who are too embarrassed to ask for help in math class to speak up to get the help they need.

Tara Lazar is a children’s book writer, but she also shares other books on her blog that her readers will enjoy. Read her post and you will know what inspired Erin Dealey to write a great introduction to fractions, The Half Birthday Book. The whimsical illustrations were drawn by Germán Blanco.

Bound for Escapes Reviews The Math Kids: An Incorrect Solution, and says that “whether a child likes math or not, this is a fun story.”

Pages Unbound Reviews Talia’s Codebook for Mathletes by Marissa Moss. This is a book that is sure to appeal to students in middle grades as Talia navigates middle school, refusing to give in to those who doubt her mathematical abilities simply because she is a girl.

A Kid’s Book a Day reviewed The Probability of Everything by Sara Everett. This book will engage 4th – 7th graders in discussions about probable and improbable events. Pelicans and Prose reviewed the same book and described The Probability of Everything as one of the most powerfully written books one could read.

The Christian Fiction Girl reviewed Calculated, by Nova McBee. It is a young adult novel that’s a blend of Mission Impossible and The Count of Monte Cristo.

Numbers on the Number Line:

Positlive compares where we are in life to additions and subtractions of positive or negative numbers on a number line in Life’s Simple Equation: Number Lines, Arithmetic, and Five Life Lessons.

Poetry for Finding Meaning in the Madness, Just Poetry wrote Odd, a poem about the life of an odd number.

You can read or listen to Keith’s Ramblings story, Unlucky Numbers. How many ways can the number 13 be partitioned anyway?

Help from Heaven has a completely different take on that number in 13 is My Lucky Number.

You’ll have to scroll down to get to the 4th-grade math sections in this post from Teaching to the Beat of a Different Drummer, but it will be well worth it. On day 3 there is a Me in Numbers activity, on day 4 a rounding to the nearest hundred activity, on day 5 a doubling single digit numbers game, and on day 6 a mind-blowing partial sums strategy.

Writing from the Heart with Brian notes that 50000 doesn’t look much different from 50000000 until you can actually relate something to each of the numbers. This insight may be helpful to your students.

The Internet Effect also discusses relative place value in The Illusory  Arithmetic: A Tale of $30 K and $300 K.

Exponential Growth:

A Berg’s Eye View shares a priceless meme to help your students remember the meaning of Exponential Growth.

Lino Matteo will open students’ eyes with the role of exponential growth in Financial Literacy: Housing.

Sumant shows his work for this SAT question on Exponential Growth.

Mathematical Games and Puzzles:

Math File Folder Games has directions to play a drawing game that will reinforce several geometry concepts AND lists the standards that the game can cover.

The Bad Mathematics blog discusses the card game 24 where the players must use addition, subtraction, multiplication, and/or division on the 4 cards they are dealt to arrive at the number 24.

The Napier Local Arithmetic Board will feel like a game as students use it as they peg to multiply numbers.

Puzzle a Day invites you to determine where is the only safe place to stand in 1500 People in a Circle. Any guess is more likely fatal than not.

A safer puzzle to answer is Puzzle a Day’s The Mystery Middle Digit.

Quadratablog.blogspot has made a sudoku puzzle that is mathier than most in a Small Multiples Sudoku.

Geometry:

The world’s geography in geometric shapes:

The Craft of Coding very much enjoyed writing code to calculate the volume of a gugelhupf pan (what I would call an angel food cake pan.) The post explains the advantages of baking when the volume of such a pan is known.

Graphs and The Coordinate Plane:

Here’s my contribution to the carnival: I made a polygonal elephant using the Cartesian coordinate system. Using Desmos, I was able to do several reflections in mere seconds: I reflected the elephant over the x-axis and the y-axis, and then reflected the reflections into the 3rd quadrant.

Nicholas C. Rossis blogged a little about the Cartesian coordinate system and shared a hilarious video in The Shape of Stories, According to Kurt Vonnegut.

Roro’s Adventurous Blog discusses vectors in Fun with Random Numbers and Matrices.

The Golden Ratio and Fibonacci:

Puzzle a Day asks that we analyze the numbers in the Fibonacci sequence in a Fibonacci puzzle.

Nature Notes the Arb shares pictures of Fibonacci numbers in nature.

On a more serious note, HTT Network has written a beautiful post Unveiling the Enigmatic Golden Ration: Unlocking the Secrets of Beauty and Harmony.

The Graphxhub blog gives us How Math in Graphic Design Adds up to Stunning Visuals. This post helped me understand the golden ratio in art much better, but it covers so much more than that.

Lego Math:

Shapes in Blue has created some lovely blue geometric Lego art you’ll want to see.

Alison Kiddle used Legos to make 31 math conversation starters, one for each day of the month of August. These three are only a sample. Check them all out!

Multiplication:

How about a Multiplication Magic Show from ActiveWordZ to help students learn the 2 and 3 times tables? It sounds pretty exciting to me!

The Reflections and Tangents blog teaches Area Arrangements going from one-digit multiplication problems to multiplying numbers with several place values, to fraction multiplication, and even to multiplying polynomials.

Mathematics History Museum:

Learn the history of the Rubik’s cube as you walk through MillenialMatriarch’s post on Rubik’s Magic Cube.

Sheryl, a Hundred Years Ago explains how recommended calories were calculated in 1923 and compares it to the method used today.

Cedric School of Thought describes the difficult life of self-taught mathematician, Nicolo Tartaglia, in the 16th century.

Visit Live Life King Size for a lovely presentation, What is the History of Maths? It is perfect for our Museum of Mathematics.

Math Through Music:

I saved my favorite for last:

Want more? Playlistideas has compiled a playlist of artist-produced songs about math just for us all to enjoy!

Mathematical Optical Illusions and Photography:

What carnival would be complete without a house of mirrors?

Zsolt Zsemba wrote a post explaining why a few mathematical designs turn into optical illusions.

Mathematics and art combine to make a rug that looks dangerous to step on.

Click on the video at Terryorism’s blog and watch some squares look like they’re moving, but they aren’t.

Enchanted Seashells shared these squares that are drawn to look like a stairway that changes direction while you’re looking at it.

Let’s Write… saw a picture of real stairs that look like they could be going up just as easily as they are going down and wrote about it.

Robert’s Snap Spot shared An Optical Illusion at Shelter Cove with some cool shadows. This photo really exemplifies perspective in art as well as in mathematics.

Travel with me takes us to a photo gallery highlighting triangles in each frame.

The Other Life of This Math Teacher is Photography: See the geometry in
Make Friends, Have Fun,
in Penta-licious,
and in a Chinese Pagoda.

Paper Folding, Origami, and Tangrams:

Carter in the Classroom reported to an NBC affiliate how A Texas Teacher Uses Origami to Teach Math (and a Growth Mindset).

Paula Beardell Krieg has produced some wonderful blogposts on paper folding this summer:

Paula Beardell Krieg also wrote several wonderful posts on exploring geometry through tangram play.

Geometric Designs and Tessellations:

RobertLovesPi regularly makes and shares tessellations of his blog. His tessellation of octogons, rhombi, and darts is very pretty. Be sure to check out his tessellation which includes heptagons! I don’t think they show up in other people’s tessellations very often.

You may have heard of the newly discovered tessellating hat, or maybe even the new tessellating turtle, but have you heard of David Smith’s tessellating Spectre?

Pascal’s Prism teaches us about the hidden math behind art: the fascinating geometry of tessellations.

Geometric designs might be done with plastic, paper, or cloth. Pieced quilts can certainly bring pleasure to those who make them as well as those who look at them. Take a look at these recent blog posts featuring some lovely quilted geometric designs and tessellations:

  1. Sailing Ships made from circles and squares,
  2. Intersecting Circles,
  3. Triangles,
  4. A Sampler with a variety of designs, any of which could tessellate an entire quilt.
  5. A Design made with squares in a couple of different sizes.
  6. Parallelograms (Scroll down a little to see them.),
  7. A Square and Triangle design with a free pattern and instructions,
  8. A Flower made with mini hexagons,
  9. Maple Leaf (very nice for autumn),
  10. A Mystery Halloween Quilt,
  11. A Halloween Lap Quilt,

Sets

Read and Play All Day will help us all put objects into sets with Sorting and Ordering by Size: A Precursor of Ordering Numbers.

Elorine takes 5th-graders on a few adventures. The first is Unleashing the Power of Sets, A Magical Math adventure.

The second is a virtual field trip, Exploring the Wonderful World of Sets. Find Treasures Within.

The third is Exploring the Magic of Union Sets in Mathematics.

The fourth is The Marvelous World of Equivalent Sets.

Probability and Statistics:

Wind Kisses discusses the likelihood of certain events and shares some inspirational quotes in Likely or Unlikely.

There are 23 players on a soccer team, what is the probability that at least two of the players have the same birthday? That question was examined at the Women’s World Cup, and the answer may surprise you!

Statistical Odds and Ends asks, “What is the probability of getting all heads on multiple coin flips?”

Every Saturday Nebushumor publishes a funny statistics post. For example, take a look at How I Use My Recreational Time. You and/or your students can probably relate to it. Or how about Fun, by Decade. I think he’s spot on.

Thoughts on Teaching Mathematics to All Students:

Denise Gaskins is very impressed with a fully developed, revolutionary program that teaches Algebra before Arithmetic and wishes she had access to it 30 years ago when her kids were young.

You can read the importance of a growth mindset from a parent’s perspective in The Power of Yet.

Heidi Allum asks if Math Play can be a Part of Trauma-Informed Care? I’m sure you will be interested in learning how math play affects all students including those who have experienced trauma.

Don’t let the solved calculus problem at the beginning of the post intimidate you, but Alternative Amie has several insights into the benefits of melding the arts with the teaching of mathematics.

Other Carnivals with Mathematics:

Every month The Aperiodical blog also coordinates a math carnival that includes college-level mathematics. September’s carnival is at Reflections and Tangents.

The last Playful Math Carnival was at Learning Well at Home. The next one will be at Math Hombre. How about a future carnival being on your blog? Volunteers are needed and welcome! Coordinate with Denise Gaskins for a month that is convenient to you by going to the Playful Math Carnival Volunteer Page.

1766 A Polygonal Elephant for World Elephant Day

Today’s Puzzle:

Today many people are reflecting on the plight of elephants throughout the world and what we can do to protect them and their habitats. Yesterday I created an image of a lone elephant in Desmos:

Today’s puzzle is to take the Desmos Elephant image and transform it as I have done below. There is no need to retype all the ordered pairs that made the elephant. One of the reflections was made simply by typing “polygon(x1,-y1)” below all the order pairs in the Desmos image. Can you determine which reflection that was? What was typed inside the parenthesis to make the other two elephants?

How would the elephant be transformed if you typed “polygon(-y1,x1)”, “polygon(x1+5,y1)” or  “polygon(2×1,2y1)” below the ordered pairs in Desmos? Can you figure out a way to shrink the elephant and make it upside down in the first quadrant? I hope you will take the time to check out these transformations and experiment with some of your own.

Factors of 1766:

  • 1766 is a composite number.
  • Prime factorization: 1766 = 2 × 883.
  • 1766 has no exponents greater than 1 in its prime factorization, so √1766 cannot be simplified.
  • The exponents in the prime factorization are 1 and 1. Adding one to each exponent and multiplying we get (1 + 1)(1 + 1) = 2 × 2 = 4. Therefore 1766 has exactly 4 factors.
  • The factors of 1766 are outlined with their factor pair partners in the graphic below.

More About the Number 1766:

1766 looks interesting in some other bases:
It’s 6E6 in base 16 because 6(16²) + 14(16) + 6(1) = 1766,
272 in base 28 because 2(28²) + 7(28) + 2(1) = 1766, and
123 in base 41 because 1(41²) + 2(41) + 3(1) = 1766.

1765 On This Memorial Day

Today’s Puzzle:

This weekend I laid a bouquet of red and white flowers on my husband’s grave and decided to make a red rose Memorial Day puzzle for the blog as well. It is a mystery-level puzzle.

Write the number from 1 to 12 in both the first column and the top row so that those numbers are the factors of the given clues. There is only one solution.

Factors of 1765:

  • 1765 is a composite number.
  • Prime factorization: 1765 = 5 × 353.
  • 1765 has no exponents greater than 1 in its prime factorization, so √1765 cannot be simplified.
  • The exponents in the prime factorization are 1 and 1. Adding one to each exponent and multiplying we get (1 + 1)(1 + 1) = 2 × 2 = 4. Therefore 1765 has exactly 4 factors.
  • The factors of 1765 are outlined with their factor pair partners in the graphic below.

More About the Number 1765:

1765 is the sum of two squares in two different ways:
42² + 1² = 1765, and
33² + 26² = 1765.

1765 is the hypotenuse of FOUR Pythagorean triples:
84 1763 1765, calculated from 2(42)(1), 42² – 1², 42² + 1²,
413 1716 1765, calculated from 33² – 26², 2(33)(26), 33² + 26²,
1059-1412-1765, which is (3-4-5) times 353, and
1125-1360-1765, which is 5 times (225-272-353).

1765 is a digitally powerful number:
1⁴ + 7³ + 6⁴ + 5³ = 1765.

1765 is a palindrome in a couple of different bases:
It’s A5A base 13 because 10(13²) + 5(13) + 10(1) = 1765, and
it’s 1D1 base 36 because 1(36²) + 13(36) + 1(1) = 1765.