Foundation and Higher · one quantity as a fraction of another
One amount as a
fraction of another.
same units first,
then simplify
the word that sets the denominator —
of
15 as a fraction of 40
the number after “of” goes below
step 1 of 4
Write it, simplify it
1. First number on top, “of” number below.
2. Simplify: divide both by 5.
✓ 15 is 38 of 40
15 as a fraction of 40
1540
= 38÷ 5
step 2 of 4
Same units first
1. Pence and pounds cannot be mixed.
2. Change both into pence, then simplify.
✓ 15, not 402
40p as a fraction of £2
£2 = 200p
40200
= 15
step 3 of 4
With time
1. Change the hours into minutes.
2. 45 over 120: divide both by 15.
✓ Always the smaller unit for both
45 minutes of 2 hours
2 hours = 120 minutes
45120 = 38
step 4 of 4
It can be more than 1
1. The order does not change: 50 on top.
2. 50 is two and a half lots of 20.
✓ Never swap them to make it look right
50 as a fraction of 20
5020
= 52 = 212
as a fraction of —
Order
first amount over the “of” amount
Simplify
always, to finish
“Of” tells you
what goes on the bottom.
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