Neat math online and some fun number patterns for kids

I’ve mentioned several times before that I’m amazed by all of the great math that gets shared on Twitter.  One specific thing that I’ve done more of with my kids as a result of seeing all of the work that teachers are sharing is spend time talking about patterns.

Three examples showing some of the fun math that people are sharing on line are:

(1) Fawn Nguyen’s site,,  which I’ve mentioned a few times before,

(2) Patrick Honner’s visual proof that the series 1/4 + 2/8 + 3/16 + 4/32 + 5 / 64 + . . . . = 1.  That post is here:

(3) Evelyn Lamb’s post about Cycloids:

With that background, I was talking through a problem from an old MOEMs math contest with my kids last night.  The thing that you needed to notice in the problem was that 1 + 2 + 3 + . . . + 14 + 15 = 120.  Not a particularly interesting fact all by itself, but as we were talking through the problem my younger son started asking me about several different pattern that he saw in the numbers.  That short conversation last night led to a slightly  more in depth conversation this morning:

I’ve not really known what to make of all of the math education articles flying around in the NYT (and various other places) during the last few weeks.  Sort of feels like we’ll be having the same conversations about math and science education for years and years and years.  What I do know for sure, though, is that I’m glad that I get to see all the cool math and science stuff people are sharing on Twitter and also glad that I get to use that material to help me have these fun conversations about math with my kids.