Ladies and gentlemen welcome to the Playful Math Education Blog Carnival! This month’s carnival features the versatile number 135. It is the smallest number whose digits are the first three odd numbers. Watch 135 perform these AMAZING stunts:

**135** = **1⁵** x **3****³** x **5****¹**

**135** = (**1**+**3**+**5**)(**1**×**3**×**5**)

**135** = **1**¹ + **3**² +**5**³

135 made that last one look as easy as 1-2-3.

### Carnival Wait Times

Now before we get started with our playful math blog posts, I would like to address wait times. Every worthwhile amusement park and carnival has lines in which people must wait. The playful math carnival loves lines and is no exception, but is waiting really a bad thing? In Solving 100÷3 Mentally: a Surprise, Marilyn Burns teaches and assesses children’s understanding of mathematics. She explains that patiently waiting for kids’ mathematical thoughts can actually speed up their understanding and enjoyment. Hence, it is all worth the wait!

Mr. Mathematics also waits patiently for his students to think problems through themselves. When an inspector tried to interview him about issues he faces in his department, he turned the tables and talked about his students’ learning so much because he waits patiently for his students to problem solve.

### Art

Robert Loves Pi has makes gorgeous mathematical art. For example, he’s made this design with circles, triangles and a pentagon and a beautiful rotating arrangement of a pentagrammic prism.

Since it is February, Colleen Young collected a very nice assortment of hearts related to mathematical content.

Mike and his sons of Mike’s Math Page produced some lovely geometric designs in A Fun Zometool project with Decagons.

Paula Beardell Krieg has published several blog posts on Frieze symmetry. Here is the start of that series of posts:

### Education

I’ve seen the visual below several times before, but I didn’t realize its magnificence until I read Sara VanDerWerf post describing how she has used it to inspire herself, her students, and other teachers:

Ben Orlin has tips from four math teachers on what makes a teacher great:

### Food Court at the Math Carnival

Here’s a tasty blog post:

### Geometry

Did you know that 81² + 108² = 135²? That’s simply 27 times 3² + 4²= 5², the most famous example of the Pythagorean Theorem. The scarecrow from the Wizard of Oz sounds impressive when he recites something that sounds a little like the Pythagorean Theorem. Is the formula he gives true? Watch this short movie clip and tell me what you think:

Check out these geometry blog posts I saw on twitter:

### Language Arts and Math

If you just asked students to write something about math, they might not have much to say, but if you gave them some of the wonderful prompts suggested by CLopen Mathdebater in Explore Math with Prompts, you might just be as pleasantly surprised as she was with her student’s writing and mathematical thinking!

Intersections–Poetry with Mathematics writes about a particular subject we’ve all seen in both word problems and nightmares: Those Trains in Word Problems–Who Rides Them?

Kelly Darke of Math Book Magic has been reading picture books about counting with her child. She explains why they found the picture book, 1-2-3 Peas, to be magical. She loved watching her child trace the illustrated numerals as they explored bigger numbers like 80 and made connections between numerals and the letters of the alphabet.

### Math News Room

Here are some news articles related to math that I enjoyed reading this month:

### Museum of Math

Pat’s Blog can tell you what mathematical event happened on today’s date. For example, here is mathematical history for February 10.

Life Through a Mathematician’s Eyes shares the highlights of a history of mathematics for January.

The following images would fit in perfectly in any math museum:

How about these optical illusion?

### Probability and Statistics

Fraction Fanatic has been sharing resources every week since the beginning of 2020. In the first post of the year, This week, Number 1, we see ways to make leaf and stem plots and to make predicting probability both pertinent and fun.

Joseph Nebus regularly shares mathematically themed comics on his blog. In this one, he shares a comic that points out that those probabilities pertain to you personally, not just everybody else.

### Puzzles

Mathtuition shares a math puzzle that will get kids in primary school thinking in Marbles Math Question.

Here are some other mathematical puzzles from blogs that I saw on twitter:

### Strategies

K-8 Math Specialist Jenna Leib writes about learning and having fun with ten frames and tiny polka dots in Kindergarten Debate: Building Appreciation for Ten Frames. By the way, it’s the kindergarteners who are debating, not adults!

Given two ordered pairs, how do you find their midpoint? Don’t use some cheap trick. Math Chat has a midpoint strategy that students will remember forever, and it promotes mathematical understanding.

The writer behind Math QED earned a 770 on the math portion of the SAT and lists strategies to help you get a perfect score on that part of the test as well.

Here are a couple more blog posts about strategies that were shared on twitter:

### More Carnivals

I hope you enjoyed all the attractions at this month’s Playful Math Education Blog Carnival.

Last month the carnival was hosted by Math Misery?, but so far no one has volunteered to host the carnival for the end of March. Perhaps you will consider hosting it! It is a lot of fun exploring other people’s blogs and selecting what to share, so do think about hosting it next month or some other time in the future. Click here to volunteer to host or to submit one of your posts to the carnival.

You may also want to check out February’s Carnival of Mathematics hosted by Stormy at Storm Bear World.