## Lesson: Two-Digit Subtraction With Regrouping

Introducing the Concept

Children will analyze and solve problems using skills and strategies. Remind children that they worked with subtraction last year, and earlier this year they subtracted facts and used different strategies, which they will now use to subtract two-digit numbers. Also remind children that addition and subtraction are related operations.

**Materials:** overhead projector, tens and ones workmat, bundles of 10 craft sticks and single craft sticks, large number line, and large hundred chart

**Preparation:** Prepare a tens and ones workmat for use on the overhead. Make nine bundles of ten craft sticks. Make a large number line and hundred chart for the classroom.

**Prerequisite Skills and Concepts:** Children should know the subtraction facts to 20 and the strategies used in learning them. See Addition and Subtraction Facts to 20.