number trees



We've been working on a bit of subtraction action around here.  The kids love workbooks, but I have a hard time believing they "really do the job."  If there isn't some drawing or making involved, then mama thinks it doesn't count.  They enjoy subtracting in their heads, when collecting change while playing bank or store.  And this is great.  But as their main educational support, I need color to keep from falling asleep.  When I first tried to line up double-digit subtraction in a vertical format, ie,




 -    2




= 32


I was kicked off the learning table.  "Yes, And, you're not really making sense, SO, please let us just do this!"  For some reason they could do the problems horizontally, though, as in


34 - 2 = 32.


I happen to believe this lacks juice & drama, though, which in turn makes me start shooing them away from the learning table, to more interesting things, like, wood-stacking & fire-making.  So these trees were my next attempt.  Bingo! 


We keep the 10's on the left side of the tree, & the 1's on the right.  They color in the leaves, using a different color for the leaves that will get subtracted.  They totally got it.  The next time we do this, I'm going to put longer branches on the left, with 10 leaves to each branch.  And we'll make short branches on the right, each holding just a single leaf.  It won't look as balanced, but I think it will really drive the point - that there's 10's & 1's, home, & make it easy to illustrate estimating. I'll show you when we get there!