Subtraction and Answer Checking

Subtraction and Answer Checking

What students learn

Students learn that subtraction can reverse the same hand-counting pattern they used for addition. Open with Chisanbop Subtraction Reverses the Counting Pattern to connect subtraction to moving backward.

Why it matters

Subtracting with finger values can become confusing if tens and ones blur together. Chisanbop Subtraction Manages Tens and Ones helps students keep the values separated.

Learn the idea

Because this is an enrichment strategy, students should still be able to check the result another way. Chisanbop Strategy Checks Answers With Standard Math shows how to compare the hand answer with written math.

Try it

Ask the student to solve 9 - 4, 13 - 6, and 21 - 8 using hand positions. For each problem, have them check by adding the answer back to the subtracted amount.

Parent guide

Celebrate clear thinking more than speed. If the answer is wrong, ask the student to replay the hand moves and say each value aloud.