Step by step
The question
Question: A coat costs $80.
It is 25% off.
What is the sale price?
1 Find the discount
Percent means out of 100.
So 25% is 25 divided by 100: 0.25.
The point moves 2 places to the left.
25% = 25 ÷ 100 = 0.25
The discount is 25% of $80.
"Of" means times: 0.25 times $80.
To multiply decimals: first 25 times 80, as whole numbers.
That is 2000.
Then count the decimal places: 2, the digits after the point in 0.25.
So it is 20.00.
25 × 80 = 2000
2 decimal places: 20.00
So the discount is $20.
discount = 0.25 × $80 = $20
Careful!
The discount is the money we save.
We still pay the rest.
Careful: $20 is what we save, not what we pay
2 Take it off
A discount comes off the price.
$80 minus $20 is $60.
sale price = $80 − $20 = $60
So the sale price is $60.
3 Check
Let's check another way: we pay 100% minus 25%: 75% of the price.
0.75 times $80 is $60.
The same.
So the answer is right!
100% − 25% = 75%: 0.75 × $80 = $60
Let's look back.
First: find the discount.
Then: take it off.
Last: check.
Answer
sale price = $80 − $20 = $60