Alli's been very excited about Algebra recently and has burned through Hands on Equations, so I wanted to get her the Algeblocks I remember from my math ed grad program. What I discovered, quickly, was that those suckers are a) expensive and b) not available in any quantity below study group size, which, for one child working at home alone, doesn't quite fit our needs. I found printable versions, but making a 3d item 2d in many ways makes them inferior to Algebra tiles, which are designed to be 2d.
So, I was thrilled when I found a lot of Algeblocks on Ebay, which I got for $10 including shipping. I could tell that the green 1 cm unit cubes were missing, but we have enough math manipulatives around that I knew I could substitute something, and that if I wanted green I could probably buy them quite cheaply, so that didn't worry me.
What I'd missed, though, until I got the box today, was that I was missing the X and Y rods. And Algeblocks are designed so that the X and Ys are NOT a whole multiple of units, making substituting with Cuisinaire rods not an option unless I wanted to do some really, really exact sawing.
But where there's a will, there's a way-especially in a house full of legos. As it turns out, X's are exactly the length of a 4 peg lego brick, and a 1x4 fits the factor track quite well. 1x6 works almost as well for Y! So, we dug through the most common colors in Alli's lego bin and easily found a large handful of Xs and Ys to build equations with. And 1s, too, since we decided to keep with the theme.
We decided against matching the Algeblock colors because orange is a rare color for legos, and even Yellow isn't the most common color in the sets Alli enjoys. But between Pharoah's Quest, Castle, Harry Potter, and other sets with buildings, we're long on beige and grey, so we picked beige for X, grey for Y, and dark grey for 1.
The best part of this is that I'd downloaded the Algebra Lab Gear manual, which mostly, but not quite, works with Algeblocks. The primary difference is a few specific pieces. Since we've discovered that legos are compatibly sized, that lets me build any extra pieces we need.
So, if you're considering algeblocks, consider getting out the legos!