# Comparisons

Achievement Objectives
NA2-3: Know the basic addition and subtraction facts.
NA2-3: Know the basic addition and subtraction facts.
Specific Learning Outcomes

Recall addition and subtraction facts to 20.

Description of Mathematics

Number Framework Stage 5

Required Resource Materials
Recall addition and subtraction facts to 20.
Activity

#### Using Materials

Problem: Martin has \$7 and David has \$3 more than Martin. How much money does David have?
In pairs the students build a line of 7 counters for Martin and experiment with building David’s line along side Martin’s. Discuss why the answer is found by 7 + 3.Write 7 + 3 = 10 on the board.

Problem: Tusi has \$11 and Mere has \$8 less than Tusi. How much money does Mere have?

In groups the students build 11 for Tusi and experiment with building Mere’s line. Discuss why the answer is found by 11 - 8. Write 11 - 8 = 3 on the board.

Examples. Comparison word stories and recording for: 8 + 3, 11 – 2, 7 – 3, 11 – 5, 7 + 3, 4 + 5, 10 - 8….

#### Using Imaging

Shielding  and  Imaging Only:
Examples. Comparison word stories and recording for:  2 + 6, 12 – 4, 7 – 6, 11 – 2, 4 + 5, 2 + 11, 10 - 4…

#### Using Number Properties

Examples: Comparison word stories and recording for: 28 + 6, 12 – 4, 7 – 6, 11 – 2, 4 + 5, 2 + 11, 10 - 4…