W7.5

Front

W7.5

Work out (without a calculator!):

30% of 80cm

Back

Hint:

To work out percentages remember those few key ones:

50% = 1/2 = ÷ 2

10% = 1/10 = ÷ 10

1% = 1/100 = ÷ 100

bonus one (but not essential): 25% = ÷ 4

25 % = 1/4 = one quarter

Then use those key percentages to workout the one you want, you can multiply, divide or add them.

e.g.: 30% = 3 x 10%

Front

two more questions:

work out:

5% of 90km

25% of 64ml

Back

answers:

30% of 80cm

10% = 8

30% = 3 x 8 = 24 cm

5% of 90km

I can do 1% x 5 or 10% ÷ 2

10% = 9

5% = 9 ÷ 2 = 4.5km

25% of 64ml

I can do 10% + 10% + 5%

or ÷ 4 or ÷ 2 and ÷2 again

64 ÷ 2 = 32

32 ÷ 2 = 16ml