Step by step
The question
Question: change £300 to dollars, when £1 = $1.27.
£1 = $1.27. Change £300 to dollars.
1 Write the rate
The rate says: 1 pound is worth 1.27 dollars.
£1 = $1.27
From pounds to dollars, we multiply by 1.27.
Going back, we divide by 1.27.
pounds → dollars: × 1.27
dollars → pounds: ÷ 1.27
2 Multiply by the rate
Each pound is worth $1.27.
300 pounds are worth 300 times as much.
£300 = 300 × $1.27
To multiply decimals: first 300 times 127, as whole numbers.
That is 38100.
Then count the decimal places: 2.
So it is 381.
300 × 127 = 38100
2 decimal places: 381
So 300 times 1.27 is $381.
= $381
Careful!
Check the direction.
Pounds to dollars: we multiply by the rate.
Careful: pounds → dollars: × the rate
So £300 is $381.
3 Check
Let's check: change the answer back.
$381 divided by 1.27 is £300.
change it back: $381 ÷ 1.27 = 300
That is what we started with.
So the answer is right!
£300 — what we started with
Let's look back.
First: write the rate.
Then: multiply by the rate.
Last: check.
Answer
= $381