This is a level 2 number activity from the Figure It Out series. It relates to Stage 5 of the Number Framework.
Click on the image to enlarge it. Click again to close. Download PDF (129 KB)
use addition facts to solve puzzles
FIO, Level 3, Basic Facts, Array Puzzles, page 8
Students enjoy making and completing arrays for both addition and multiplication facts. Students are often given arrays to complete where the addends are provided and they have to find the sum, such as the array in question 1.
Question 2 offers an interesting and challenging alternative because it has missing addends and sums. Students need to recognise that addition and subtraction are inverse operations and to be able to consider the facts in different forms. For example, to find out what number goes in the top right corner of the first array, they need to find the unknown in this equation: 9 + = 17. Seeing that
addition and subtraction are inverse operations, they can rewrite this as 17 – 9 = and solve the problem this way.
As a variation to this activity, students might like to use this same method and design multiplication arrays for classmates to solve.
Answers to Activity
Answers will vary.