In too many cases, subtraction with regrouping is learned as a step-by-step procedure. It's true for me. When I learned to subtract with regrouping, my elementary school teacher taught me the steps - not actually what was happening with the numbers. Because I just learned a process, I sometimes became confused with the steps and made mistakes. Because I just learned a process, I struggled with number sense and estimation. I didn't really understand how numbers worked together. I didn't want this to happen to our kids. So - to learn a conceptual understanding of regrouping, we used base ten blocks to demonstrate what was actually happening when we "cross out" a number and change it into another one. We started by using this incredible website to actually see the base ten blocks in action, then we moved to using base ten blocks on our own. Students had to use the base ten blocks to explain exactly what was happening in each step. I was really proud of our kids for the understanding they gained this week.
Sunday, September 5, 2010
Subtracting with Base Ten Blocks
Tuesday, August 24, 2010
Adding with Base Ten Blocks
After spending our first week of math workshop playing games and figuring out puzzles, I wanted to spend this week using base ten blocks. Yesterday in class, we used base ten blocks to demonstrate our understanding of regrouping in addition. Most kids know to start by adding the ones place, and sometimes you have to "carry the one." But it's not really a "one," is it? It's really a ten. And when kids add the tens place, they often times have to "carry the one" over to the hundreds place. But it's not really a "one" - it's really a hundred. The base ten blocks gave us a concrete understanding of this concept. I'm always pushing for kids to understand the WHY behind math. I want us to go beyond the procedures and steps and really develop a conceptual understanding of how numbers work. Below are some pictures of our kids at work.
