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?*