## Lesson: Two-Digit Addition With Regrouping

Developing the Concept

Once children are comfortable using different strategies to do two-digit addition with regrouping, have them apply these strategies to paper-and-pencil activities. The use of manipulatives such as tens and ones blocks, craft sticks, and beans will be helpful. Children will use many of the same strategies that they used in Addition and Subtraction Facts to 20. Encourage children to share their thinking as they work through the examples.

**Materials:** 9 bundles of 10 craft sticks and single sticks, pencils, paper

**Preparation:** Have the large hundred chart and number line you made for “Introducing the Concept” available.

**Prerequisite Skills and Concepts:** Children should know addition facts to 20 and the strategies used in learning them.

**Wrap-Up and Assessment Hints**

Children need practice with two-digit addition and the strategies used to do it. If the sum for a problem is not correct, ask the child how he or she might go about figuring out the correct answer. Find out what children are thinking and then select a strategy that builds on what they already know. Encourage children to use strategies and related addition facts.