Unit 5 – Multiplication and division
Multiplying by 2 and 4
Winston knows that multiplying by two is the same as doubling but he is stuck when doubling all the numbers to 20. What strategies could you show him?
Look at the towers of cubes.
1
How many cubes in total in each set of 3 towers? First set: 2 + 2 + 2 = 6 and 3 × 2 = 6 Second set: 4 + 4 + 4 = 12 and 3 × 4 = 12
2
Each tower of four cubes is made up of 2 towers of two cubes.
1 How many cubes will we need to make the following towers?
(b)
(a)
+
+
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=
+
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=
×
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×
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2 How many cubes will we need to make these towers? 4 towers of 4 cubes + + + = × = 5 towers of 4 cubes + + + + = × =
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03/05/2022 10:18
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