Step by step
The question
Question: change 5 feet into inches.
5 ft = ? in
1 Find the link
1 foot is 12 inches.
1 ft = 12 in
2 Make the unit fraction
We want inches, so inches go on top.
We have feet, so feet go at the bottom.
Top and bottom are the same amount.
So the fraction is 1, and times 1 keeps the size.
12 in1 ft = 1
Careful!
Not upside down.
Then the feet would not cross out.
Careful: not 5 ft × 1 ft12 in ✗
3 Multiply
We multiply 5 feet by the fraction.
5 ft = 5 ft × 12 in1 ft
Feet on top and at the bottom cancel, like numbers.
Cross them out.
Inches are left.
What is left: 5 times 12.
= 5 × 12 in
5 times 12 is 60.
So 5 feet is 60 inches.
= 60 in
4 Check
Does it make sense?
Inches are smaller than feet.
So we need more of them.
60 is more than 5.
Yes.
in smaller than ft → more: 60 > 5
And back the other way: 60 divided by 12 = 5.
We get 5 feet again.
So the answer is right!
back: 60 ÷ 12 = 5
Let's look back.
First: find the link.
Then: make the unit fraction.
Then: multiply.
Last: check.
Answer
= 60 in