Step by step
The question
Question: A meal costs $45.
The sales tax is 8%.
What is the total cost?
1 Find the tax
Percent means out of 100.
So 8% is 8 divided by 100: 0.08.
The point moves 2 places to the left.
8% = 8 ÷ 100 = 0.08
The tax is 8% of $45.
"Of" means times: 0.08 times $45.
That is $3.60.
tax = 0.08 × $45 = $3.60
To multiply decimals: first 8 times 45, as whole numbers.
That is 360.
Then count the decimal places: 2.
So it is 3.60.
8 × 45 = 360
2 decimal places: 3.60
Careful!
8% is not $8.
It is 8% of the price.
Careful: not $45 + $8 = $53 ✗
2 Add it on
The tax is added to the price.
$45 plus $3.60 is $48.60.
total = $45 + $3.60 = $48.60
So the total is $48.60.
3 Check
Let's check another way: we pay 100% plus 8%: 108% of the price.
1.08 times $45 is $48.60.
The same.
So the answer is right!
100% + 8% = 108%: 1.08 × $45 = $48.60
Let's look back.
First: find the tax.
Then: add it on.
Last: check.
Answer
total = $45 + $3.60 = $48.60