Counting by 20s, 50s, and 100s

Purpose

To build fluency at counting by 20s, 50s, and 100s.

Materials

None

Overview

Gather the class in a circle. Have the class count by 20, wdo this for exactly thirty seconds, with one number each second and no faster. When children seem excited for a new challenge, choose individuals to provide each number in the sequence. Try to have each student respond at least twice.

Optional: If children have difficulty, ask them to count by 10 silently and say every second number aloud. Or, help children relate to the pattern of skip-counting by twos, fives, or tens.

Next, start over and count by 50 and then by 100. You might want to find out which children can count to 1,000 or higher when skip counting by 50 or 100.

About the sequence

Part 1 starts with counting by 20 and eventually moves to counting by 50 in Part 2, and 100 in the extension.

Part 1

Count by 20, starting at 0. While we are skip counting, we’ll we can do this for exactly thirty seconds, with one number each second and no faster.

0, 20, 40, 60, 80, 100, 120…540, 560, 580, 600

If children need more practice or are enjoying their mastery, repeat. If children are ready to move on, move to Part 2.

Part 2

Count by 50, starting at 0. While we are skip counting, we’ll we can do this for exactly thirty seconds, with one number each second and no faster.

0, 50, 100, 150, 200…1,350, 1,400, 1,450, 1,500.

If children need more practice or are enjoying their mastery, repeat. If children are ready to move on, move to Step 3.

Extension

Count by 100, starting at 0. While we are skip counting, we’ll we can do this for exactly thirty seconds, with one number each second and no faster.

0, 100, 200, 300, 400…2,700, 2,800, 2,900, 3,000.