More multiplication
Multiplying by 50 and 25 mentally
1 We can calculate the answer to 100 × 16 in our head. Let’s use a bar model to represent this calculation.
100 × 16 = 1600
Now let’s show half of the bar. Half of 100 is 50.
100 × 16 = 1600
50 × 16 = 800
We can multiply by 50 by multiplying by 100 and then halving.
Let’s halve the bar again. Half of 50 is 25.
2
100 × 16 = 1600
50 × 16 = 800
25 × 16 = 400
We can multiply by 25 by multiplying by 100 and then halving and halving again.
Let’s Practise
(a) 64 × 50
(b) 64 × 25
(c) 14 × 50
(d) 38 × 25
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01/12/2021 14:51
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