:36 and 29
Loading Images

Approach: One to one Level: Year 4 and year 8
Focus:Multiple strategies for adding two numbers.
Resources: Card with 2 numbers.
96KB
Questions / instructions:

Show student the number card.
36
29

Year 8 version

Here are two numbers, 36 and 29. If you had to add the two numbers, and you didn’t have a calculator, how would you work it out?

Try to think of three different ways you could work it out, and explain each way to me.

Encourage student to think of, and explain, 3 ways.

They are not asked to work out answers.		 Year 4 version

Here are two numbers, 36 and 29. If you had to add the two numbers, and you didn’t have a calculator, how would you work it out?

Try to think of one way you could work it out, and explain it to me.

Encourage student to think of, and explain a way of working it out. They are not asked to work out answers.

If the student succeeds in explaining one way ask:
Is there another way could work out 36 plus 29? Explain to me how you would do it.

% responses
y4
y8

Explained a satisfactory…

• not asked for Year 4

first way
61
64
second way
16
33
third way
•
21
Commentary
Less than two thirds of students at both levels could give an oral description of a strategy that would work if carried out correctly. Considering only the first strategy, the standard addition algorithm was the most popular strategy for both year levels (28 percent of year 8 students and 18 percent of year 4 students). The simplification of adjusting the 29 to 30 was suggested by 17 percent of students at both levels.
 
Chapter Graphic
 Loading Images