## Sunday, August 18, 2013

In fourth grade, the first standard I like to tackle is CCSS 4.NBT.A.2, which gets kids reading and writing large numbers. Here's how our lesson went this week.

First, we talked about the Base-10 number system. My students had no idea what I was talking about! They tried to tell me that we have a Base-10 system because there are only ten symbols, 0 through 9. I explained that man made up the ten symbols, and that ancient civilizations had used different bases. That was a hard thing for them to swallow. "Why," I asked them, "do you think we finally decided on a Base-10 number system?" As we pondered these basic ideas in mathematics, I kept gesturing with the ten best reasons I could find:

Some of them began to catch on. They began to talk about how they learned to count with their fingers and toes: 1-2-3-4-5-6-7-8-9 and then 10 was one group of fingers. Eleven was one group of all of their fingers plus one more from a second group. They were beginning to "get" the Base-10 number system.

By and by we moved on to place value. They already understood ones, tens, and hundreds. That, I explained, was one period. The next period, also comprised of three numbers, is called the thousands period. It contains the one thousands place, the ten thousands place, and the hundred thousands place. The students were excited to know that once they knew about periods, they could read any large number. Then, of course, we had to stop to discuss millions, billions, trillions, quadrillions, quintillions, and especially google. These mathematical concepts really motivate fourth graders: it's big kid stuff!

The time had come to actually read large numbers. This poster illustrates how I teach the skill. (Just click on the image to download it.)

In no time, my students were reading big numbers. Each student read one large number aloud. When I felt they were getting the hang of it, they got in groups to read to each other, and I gave them homework for more practice. (Everyone knows that practice makes perfect.)

Reading multi-digit numbers, even really big ones, becomes a snap when kids realize that they just chunk the numbers into three-digit periods and state the period name after each. Anyone can do it!

Talking about math, really getting into the nitty-gritty of how the Base-10 number system works, is essential. Teaching mathematical processes must be coupled with strategies for grasping mathematical concepts. This is Job #1!

If you're looking for worksheets, activities, and assessments for teaching 4.NBT.A.1, 4.NBT.A.2, and 4.NBT.A.3, take a look at Multi-Digit Whole Numbers - Differentiated in my Teachers pay Teachers store.