Step by step
The question
Question: change $80 to pounds, when $1 = £0.75.
$1 = £0.75. Change $80 to pounds.
1 Write the rate
The rate says: 1 dollar is worth 0.75 pounds.
$1 = £0.75
From dollars to pounds, we multiply by 0.75.
Going back, we divide by 0.75.
dollars → pounds: × 0.75
pounds → dollars: ÷ 0.75
2 Multiply by the rate
Each dollar is worth £0.75.
80 dollars are worth 80 times as much.
$80 = 80 × £0.75
80 times 0.75 is £60.
= £60
To multiply decimals: first 80 times 75, as whole numbers.
That is 6000.
Then count the decimal places: 2.
80 × 75 = 6000
2 decimal places: 60
Careful!
Check the direction.
Dollars to pounds: we multiply by the rate.
Careful: dollars → pounds: × the rate
So $80 is £60.
3 Check
Let's check: change the answer back.
£60 divided by 0.75 is $80.
change it back: £60 ÷ 0.75 = 80
That is what we started with.
So the answer is right!
$80 — what we started with
Let's look back.
First: write the rate.
Then: multiply by the rate.
Last: check.
Answer
Careful: dollars → pounds: × the rate