Monday, September 5, 2011



I had a student ask me recently for some help with an EDC component that I call split it! Actually, I had several students ask on behalf of their parents.

There was a homework problem that asked for students to show strategies to split a number like 7,758.

What I look for is a way to make splitting the number easy by using simple mental calculations. Usually, the first step is to decompose the number into its place values. So, 7,758 becomes

7,000 + 700 + 50 + 8 . Then, I ask that a student rewrite any number that they cannot readily split. Usually, these numbers start with odd numbers. We'll look at 7,000.

7,000 could be rewritten as 6,000 +1,000 (both of which are easy to split). After that, it's all down hill.

The whole number could be rewritten as 6,000 + 1,000 + 600 +100 + 40 + 10 +8, and finding half of these numbers should be EZ! 3,000 +500 +300 + 50 +20 +5 +4 = 3,879!

1 comment:

Dee Dee Tamburrino said...

I finally understand what it means to "decompose" a number. Thanks again for another intriguing math lesson.

I am part of your "vision statement" on the right side-bar and that makes me feel important.