## Lesson: Order Whole Numbers to 100Introducing the Concept

Materials: number cards 0 – 20

Preparation: Prepare a large class set and individual sets of cards numbered from 0 – 20.

Prerequisite Skills and Concepts: Children should be able to count from 1 – 10. They should also understand order.

Place the class set of number cards on the floor in random order.

• Ask: Can we tell if a number is missing?
Elicit from children that it is hard to see if a number is missing when the numbers are mixed up.
• Ask: Can you suggest a way that we might find out if a number is missing?
Lead children to respond that they could put the numbers in order to find out if a number is missing.
• Repeat the activity again, this time removing a number.
• Ask: Is a number missing?
Encourage the children to put the cards in order and identify the missing number.
• Say: Now we are going to work in pairs (groups) to put the numbers in order.
• Break children into pairs or small groups. Give each pair or group a set of number cards to spread out randomly on the table. Then have children take turns putting the cards in order.
• As you circulate, ask questions such as, “How do you know where that number goes?” “Did you count from the beginning?” “Did you count backward?”