## Playful Math #152: Auld Lang Syne Edition

Welcome to the 152nd edition of the Playful Math Education Blog Carnival — a smorgasbord of delectable tidbits of mathy fun. It’s like a free online magazine devoted to learning, teaching, and playing around with math from preschool to high school.

Bookmark this post, so you can take your time browsing. There’s so much playful math to enjoy!

We didn’t have a volunteer host for January, so I’m squeezing this in between other commitments. This is my third no-host-emergency carnival in the last year, which is NOT sustainable. If you’d like to help keep the Playful Math Carnival alive, we desperately need hosts for 2022!

By tradition, we start the carnival with a puzzle or activity in honor of our 152nd edition. But if you’d rather jump straight to our featured blog posts, click here to see the Table of Contents.

## Math Journaling with Prime Numbers

Cool facts about 152: The eighth prime number is 19, and 8 × 19 = 152. When you square 152, you get a number that contains all the digits from 0–4. You can make 152 as the sum of eight consecutive even numbers, or as the sum of four consecutive prime numbers.

But 152 has two real claims to fame:

• It’s the smallest number that is the sum of the cubes of two distinct odd primes.
• And it’s the largest known even number you can write as the sum of two primes in exactly four ways.

So here’s your math investigation prompt:

• Play around with prime numbers. Explore their powers, their sums, and anything else about them you like.
• What do you notice? What do you wonder?
• What’s the most interesting number relationship you can find?

## New! Your Student Can Be a Math Maker

When children create their own math, they build a deep understanding of mathematical concepts and relationships.

And it’s fun!

So take a break from your normal math program to play with creative math. Students can:

### Check Out the Gallery

We have a few entries already in the Student Math Makers Gallery.

### Join the Student Math Makers

We’d love to add your students’ math to our collection and share it with viewers all around the world!

To submit a math creation, download a Math Makers Invitation and Submission Form below:

CREDITS: “Creating Math Puzzles by Sian Zelbo, the author of Camp Logic, via NaturalMath.com.

## Parallel and Perpendicular Art

I love this easy-but-beautiful math art project!

1. Print a page of dotty or lined graph paper for each student. You’ll also need a ruler and a large assortment of markers or colored pencils.

2. Students draw a line across the page, lining up their ruler with the grid points. The first line can be vertical, horizontal, or diagonal.

3. Keep drawing lines, but NEVER cross a line you’ve already drawn. Following the grid will create many lines parallel or perpendicular to each other. What angles can you identify?

4. Color as desired. For a stained-glass effect, outline the colored areas with a black Sharpie marker.

Look for more math art ideas in my FREE new book Geometric Coloring Designs 2: Create Your Own Art. Visit my publisher’s online store and click the “Free Books” button.

CREDITS: I saw this project at Cindy’s Love2Learn2Day blog. She got the idea from Zachary‘s MathActivities site.

## Prime Factor Art on a Hundred Chart

The best way to practice math is to play with it — to use the patterns and connections between math concepts in your pursuit of something fun or beautiful.

So this art project is a great way to practice multiplication. Use the prime factors of numbers from one to one hundred to create a colorful design.

First, download this printable file of hundred charts in non-photo blue (or light gray, if you’re printing in grayscale). The file includes:

• Line-by-line traditional chart, counting from top to bottom.
• Line-by-line bottom’s-up chart, counting from bottom to top.
• Ulam’s Spiral chart, spiraling out from the center.
• Blank grids for making your own patterns.

## How to Draw Minecraft Blocks

Running out of time on my Math You Can Play Kickstarter, so I better get to work on that Kickstarter Special Edition math-art book I promised to all the backers as a bonus reward.

Today I’m working on the Isometric Drawing and Impossible Figures section, because my co-op math classes had so much fun learning how to draw those.

Here’s a starter image on how to draw Minecraft blocks. At first I called them “isometric blocks” — but changing the name to “Minecraft” made the students really excited to learn. I’m not sure whether I like the pencil sketch, or if I should remake the illustrations on the computer…

Key steps:

1. Make a Y.
2. Turn it into an M.
3. Slant down for the bottom.
4. Slant up for the top.

The most common problem for beginners is that they try to make the base straight. They know a block can sit on a table, so the bottom has to be flat, right? But once students get a feel for how it goes, they can really take off and have fun.

UPDATE: The Kickstarter deals have ended, but my playful math books are still available through your favorite online store or by special order at your local bookshop. (Except for the Prealgebra & Geometry Games book, scheduled for publication in early 2021. Sign up for my email list to get the latest news.)