# Surf for More Math

## CHAPTER 8: ADDITION AND SUBTRACTION

**Lesson 5: Adding on a Place Value Mat **

Use these interactive activities to encourage students to have fun on the Web while learning about adding and subtracting two-digit numbers. Students can try these activities on their own or in pairs.

**Goal**

Model addition with base ten blocks and visual representations, and record the process symbolically.

[C, ME, PS]

**Instructions for Use**

**Base Blocks Addition** has students use base ten blocks to model grouping when adding two-digit numbers.

To use Base Blocks Addition, set the columns to 2. Group 10 ones together from the ones column and drag them into the tens column. The sum is show on the right and illustrated with the blocks. Click Next Problem to see the next problem.