Step by step
The question
Question: 3 miles in 1/2 hour: how much is that per hour?
3 miles in 12 hour
A unit rate says how much for 1 hour.
Per hour means: divide by the hours.
per hour = ÷ hours
1 Write the rate
Miles divided by hours: 3 ÷ 1/2.
= 3 ÷ 12
miles ÷ hours
Careful!
Not the other way round.
That would be hours per mile.
Careful: not 12 ÷ 3 ✗
2 Divide
Dividing by a fraction is the same as times its flip.
Keep the first number.
Change divide to times.
Turn the second fraction upside down.
÷ 12 → × 21
So 1/2 becomes 2, and divide becomes times.
= 3 × 21
3 times 2 is 6.
So the unit rate is 6 miles per hour.
= 6 miles per hour
3 Check
Let's check: 6 miles per hour, for 1/2 hour.
6 times 1/2 is 3.
That is the miles we started with.
So the answer is right!
6 × 12 = 3
Let's look back.
First: write the rate.
Then: divide.
Last: check.
Answer
= 6 miles per hour