Mathematics 5

# Surf for More Math

## Lesson 9 - Subtracting Decimals

Use these interactive activities to encourage students to have fun on the Web while learning about subtracting decimals. Students can try these activities on their own or in pairs.

### Goal

Use base ten blocks and pencil and paper to subtract decimal tenths and hundredths.

### Builds Upon

Student Book pages 114-116

### Instructions for Use

Base Ten Blocks - Subtracting Decimals lets students practice subtracting decimals tenths and hundredths using base ten blocks.

To use Base Ten Blocks - Subtracting Decimals, click the "Next Problem" button until a subtraction problem appears on the left side of the screen. To subtract the numbers, 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.

To practice subtracting decimals hundredths, click the up button beside "Decimals = 1" to increase the decimal places to 2. Then following the instructions above.

Subtracting Decimals lets students practice subtracting decimals tenths.

To use Subtracting Decimals, scroll down and click the "Start Subtraction" button. Calculate the difference between the two numbers and press the numeric button that matches your answer. The text box below the question will tell you if you are correct.