# Change Unknown

Achievement Objectives
NA1-1: Use a range of counting, grouping, and equal-sharing strategies with whole numbers and fractions.
NA1-1: Use a range of counting, grouping, and equal-sharing strategies with whole numbers and fractions.
Specific Learning Outcomes

Description of Mathematics

Number Framework Stage 4

Required Resource Materials
Sets of counters.
Activity

#### Using Materials

Problem: “A class is growing beans from bean seeds. When they leave school on
Monday, six seeds have sprouted. When they come to school on Tuesday morning, they find that eight seeds have sprouted altogether. How many seeds have sprouted
overnight?”
Discuss why the problem amounts to solving 6 + □ = 8. The students solve the
problem with counters and discuss their methods. Encourage the students to count on
by pointing at their fingers and saying “seven, eight, so the answer is two”.
Record 6 + 2 = 8 on the board or modelling book.
Examples: Word stories and recording for: 4 + □ = 6 5 + □ = 6 7 + □ = 8
7 + □ = 9 6 + □ = 8 6 + □ = 9

#### Using Imaging

Shielding and Imaging Only: Examples: Word stories and recording for: 12 + □ = 14
8 + □ = 10 12 + □ = 15 7 + □ = 11 8 + □ = 11 9 + □ = 12 ...

#### Using Number Properties

Examples: Word stories and recording for: 87 + □ = 89 43 + □ = 45
79 + □ = 83 51 + □ = 54 □ + 56 = 59 □ + 43 = 45 58 + □ = 63 ...