Playful Math Blog Carnival #166

This blog carnival has been around for 14 years. Almost every month for 14 years, someone has added a post to this collection. That's quite a long life for an internet phenomenon. (Congratulations, Denise, for keeping this going!) If you'd like to see any of the previous posts in this series, check them out here. For many years, blogs were a big part of my time online. But not so much lately.

When our number (166 now) was in the 20s, 30s, or 40s, I'd make sure to have that many links. Nope, I don't have time to find 166 great links (and you'd get tired just looking through them). But they're out there. I have learned so much from bunny hopping around the web of math bloggers over the years. And even though blogs aren't the popular thing now, most of the old ones are still out there, waiting for you to find them and get excited.

 

The 166 puzzle: It turns out that 166 is a 'centered triangular number'. If you start with a dot, and then you put a triangle around that, and a bigger one around that, etc, you get up to 166. How many triangles did you use?

 

I have just run out of envelopes. How should I make myself one? (a puzzle from Fawn Nguyen) What shape of paper will you use?

 

 

Online Mathy games

• The Dailies: When wordle came out, there were a number of mathy imitators, including nerdle, numberle (like nerdle, but you can do longer or shorter equations), mathler, numble, summle, and lots more. Most of them have vanished. More recently, Beast Academy added their All Ten game, which I'm hooked on.What's your favorite?
  
• Games Before Class (from Math Hombre, not all are math, hence "before class")
• Target Ten (from Denise Gaskins)
• Factors and Multiples Game (from nrich, I got 48 as my longest possible chain of factors and multiples. Can you beat me?)
• Do you know of other goodies? Let us know in the comments.
  

Geometry Puzzles

 

Find the blue area. 

This one stumped me (no trig required).

 

 

 This one's a lot easier.

 

 

 

 

 

 

What fraction is shaded? Catriona Shearer (@Cshearer41) made this, along with gobs more, mostly pretty challenging, which she posts on twitter. And here's a collection of over 300 of them.

 

Beyond the Games & Puzzles

• Balance Fractions (from Math for Love) looks fun.
  
• I must be on a fractions kick. This stood out for me, too. Fractions on Grids (from Henri Picciotto).
  
• In the series of young adult math novels I'm writing, circles come up in the 2nd book. An early reader pointed out that I might be mixing up circles and disks, so I re-wrote a few phrases. Here are some lovely circle lessons (from Sara VanDerWerf), where she helps students distinguish between those two ideas.
  

 

 

 

Searching for more? Some good hashtags are:  #MTBoS #ITeachMath  #Elemmathchat #MSmathchat

 

 

 

If you've seen some good math pedagogy out in the wilds of the internet, add a comment.