Mathematics 2

# Surf for More Math

## Lesson 6 - Regrouping to Subtract

Use this interactive activity to encourage students to have fun on the Web while learning about regrouping to subtract. Students can try this activity on their own or in pairs.

### Goals

Describe when to regroup for subtraction.

Record the regrouping process.

### Instructions for Use

Base Ten Block Subtraction lets students practice subtraction with and without regrouping.

To use Base Ten Block Subtraction, drag a red block over a blue block of the same size to cancel the red block out. When you have more red blocks than blue blocks in a column, drag a larger blue block from the column to the left into the column that has more red blocks than blue blocks. The block will automatically break up into smaller blocks. You can now cancel out the remaining red blocks in that column. Once you have cancelled out all of the red blocks in all of the columns, the subtraction solution will appear in the area on the far left.