Step by step
The question
Question: A TV costs $480.
It is 15% off.
What is the sale price?
1 Find the discount
Percent means out of 100.
So 15% is 15 divided by 100: 0.15.
The point moves 2 places to the left.
15% = 15 ÷ 100 = 0.15
The discount is 15% of $480.
"Of" means times: 0.15 times $480.
That is $72.
discount = 0.15 × $480 = $72
To multiply decimals: first 15 times 480, as whole numbers.
That is 7200.
Then count the decimal places: 2.
So it is 72.00.
15 × 480 = 7200
2 decimal places: 72.00
Careful!
The discount is the money we save.
We still pay the rest.
Careful: $72 is what we save, not what we pay
2 Take it off
A discount comes off the price.
$480 minus $72 is $408.
sale price = $480 − $72 = $408
So the sale price is $408.
3 Check
Let's check another way: we pay 100% minus 15%: 85% of the price.
0.85 times $480 is $408.
The same.
So the answer is right!
100% − 15% = 85%: 0.85 × $480 = $408
Let's look back.
First: find the discount.
Then: take it off.
Last: check.
Answer
sale price = $480 − $72 = $408