Mathematics 3

# Surf for More Math

## Lesson 6 - Adding 2-Digit Numbers

To encourage your child to have fun on the Web while learning about Adding 2-Digit Numbers, here are some games and interactive activities they can do on their own or in pairs.

### Goal

Add 2-digit numbers with and without regrouping.

### Builds Upon

Student Book pages 92-93

### Instructions for Use

Adding 2-Digit Numbers provides your child with strategies to mentally add 2-digit numbers.

To find the sum of the two numbers, click the 'Start Addition' button. Input the answer in the text box next to the 'Check' button, then click 'Check'. See if the answer is correct. Continue to find the sum of thenext two numbers.

The Addition Machine lets your child practice adding 1-digit and 2-digit numbers.

To use The Addition Machine, choose a skill level, type the answer in the text field, and click the red button to check it.

Base Block Addition lets your child practice addition with and without regrouping.

To use Base Block Addition, 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 addition 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 1000s column. The addition solution will appear on the left.

To add the blocks together 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 addition 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.