Units of length are exact lengths everyone agrees on.
Some units are convenient for measuring small things. Others are better for big things.
For example, it's easier to say that someone is 6 feet tall instead of 72 inches tall.
In this lesson, we'll show you how you can convert from one unit of length into any other unit of length in the US customary system.
In the next lesson, we'll cover conversions in the metric system.
The US customary system is made up of units of length like inches, feet, yards, and miles.
There's no pattern to how these units are related. You just have to memorize their conversion factors.
A conversion factor is a number used to change a measurement from one unit to another.
Let's review the conversion factors between the customary system units of length:
1 foot = 12 inches
1 yard = 3 feet
1 yard = 36 inches
1 mile = 1,760 yards
1 mile = 5,280 feet
These are the rules for converting:
Multiply when converting from a larger unit, like miles, to a smaller unit, like inches.
Divide when converting from a smaller unit to a larger unit.
Let's practice converting.
How many inches are there in 5 feet?
1 foot = 12 inches.
"Foot" is bigger than "inch".
So to get the answer, we multiply 5 feet by 12.
5 × 12 = 60
5 feet = 60 inches ✅
Great work. 👏
Convert 720 inches to feet.
We're converting from a smaller unit to a bigger one.
So, we divide 720 inches by 12.
720 ÷ 12 = 60
720 inches = 60 feet ✅
Awesome.
369 feet = ______ yards
We know there are 3 feet in 1 yard.
We're going from a smaller unit to a larger unit.
So, we divide:
369 ÷ 3 = 123
369 feet = 123 yards ✅
Excellent.
How many yards are in 15 miles?
1 mile = 1,760 yards
Because "mile" is larger than "yard", we multiply.
15 × 1,760 = 26,400
Now, we know that 15 miles is equal to 26,400 yards. ✅
Great work.
Now, start the practice to try some conversions on your own.