# Surf for More Math

## CHAPTER 6: ADDITION AND SUBTRACTION

**Lesson 4: Adding Another Way **

Use these interactive activities to encourage students to have fun on the Web while learning about regrouping to add 3-digit numbers. Students can try these activities on their own or in pairs.

**Goal**

Solve addition problems by regrouping as you add.

**Builds Upon**

Student Book pages 142–143

**Instructions for Use**

Addition of Three-Digit Numbers asks students to enter 3-digit numbers, add them together, and regroup.

Click on “New Problem”. Enter any 3-digit number in the first white box at the right side of the screen, then press “Enter.” Enter another 3-digit number in the second white box, then press “Enter” to add the two numbers together. Look at the answer to the addition problem beneath the boxes. If any column has more than 9 in it, click “Regroup” to regroup the numbers. Keep clicking “Regroup” until there is no more than 9 in each column. Then click “Check” to check your answer. Click “New Problem” to enter a new set of numbers into the boxes.

Base Blocks Addition has students act out addition problems by moving and regrouping base ten blocks. Note that students may need assistance understanding how to create a box by clicking on the screen.

At the bottom right of the screen, set the number of columns to 3 by clicking the down arrow. Read the addition problem on the right side of the screen, then move blocks from the bottom half of the screen above the dotted line to solve the problem. Click on the screen to draw a box around 10 single base ten blocks to regroup them into a set of 10, or draw a box around 10 sets of 10s to make 100. Then move the sets into the correct columns to show the answer below the addition problem at the right side of the screen. After the answer appears, click “Next Problem” to continue.