Activity 3.2a

Math Activity 3.2a: Addition with Base-ten Blocks

Purpose: Explore the set model for addition of whole numbers with base-ten blocks.

Materials: Base-ten blocks or Cool Math 4 Kids App Links to an external site. or Math Learning Center App Links to an external site.

Using the set model for addition of whole numbers, along with base-ten blocks, we can help kids visualize math.

The illustration above is for 32 + 23. To add means to combine and count. We can then put the 5 tens together to get 50 and the 5 ones together to get 5. So the sum is 55.

Here is an illustration for 27 and 16.

Use these three pairs of two-digit numbers to illustrate and explain how to use base-ten blocks to find a sum. Show the problem. Explain the solution. Show the answer.

1. 14 + 13
   
   
2. 25 + 18
   
   
3. 17 + 18
   
   
4. 56 + 67

On some of the problems above, you will have to trade ten ones for one ten. Be sure to show this trade in the illustration and state it in your explanation.