# Surf for More Math

## Lesson 7 **- Subtracting Decimals**

To encourage your child to have fun on the Web
while learning about Subtracting Decimals, here are some games and interactive
activities they can do on their own or in pairs.

**Goal**

Subtract decimals using base ten blocks and paper and pencil.

**Builds Upon**

Student Book pages 124-126

### Instructions for Use

** **

** **

Subtracting
Base-Ten Decimals lets your child practice subtracting decimals
tenths using base-ten blocks.

To use Subtracting Base-Ten Decimals , drag
a base block into a column to the left. If your child moves a block
one column to the right, it breaks apart to show the exchange, for example,
a 10-long for ten units. To group pieces to exchange the other direction,
click and hold the mouse key down while dragging a rectangle to "lasso"
the pieces. The newly grouped object can then be dragged into the next
column.

To complete a preset problem, select base 10
and click on the 'Next Problem' button. Group any pieces and drag them
into the next column. Start with the 1s column and work to the 1/1000s
column. The solution will appear on the left.

To subtract the blocks to create your own problem, click on the 'Create
Problem' button and then use the blue buttons at the top to enter blocks
above and below the dashed line. As long as there are two numbers correctly
represented in the specified base, the problem will appear on the left.
To solve it, click on the 'Begin Problem' button and then on any of
the blocks in the workspace.

Subtracting
Decimals lets your child practice subtracting decimals tenths.

To use Subtracting Decimals, click the 'Start Subtraction' button.
Estimate the difference between the two numbers and press the numeric
button closest to your estimation.