Step by step
The question
Question: A bike costs $250.
It is 20% off.
What is the sale price?
1 Find the discount
Percent means out of 100.
So 20% is 20 divided by 100: 0.2.
The point moves 2 places to the left.
20% = 20 ÷ 100 = 0.2
The discount is 20% of $250.
"Of" means times: 0.2 times $250.
That is $50.
discount = 0.2 × $250 = $50
To multiply decimals: first 2 times 250, as whole numbers.
That is 500.
Then count the decimal places: 1.
So it is 50.0.
2 × 250 = 500
1 decimal places: 50.0
Careful!
The discount is the money we save.
We still pay the rest.
Careful: $50 is what we save, not what we pay
2 Take it off
A discount comes off the price.
$250 minus $50 is $200.
sale price = $250 − $50 = $200
So the sale price is $200.
3 Check
Let's check another way: we pay 100% minus 20%: 80% of the price.
0.8 times $250 is $200.
The same.
So the answer is right!
100% − 20% = 80%: 0.8 × $250 = $200
Let's look back.
First: find the discount.
Then: take it off.
Last: check.
Answer
sale price = $250 − $50 = $200