Split It
This is an easy strategy to split a number like 7,758 in half.
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!
Try it!!