# A mile is 5280 ft long. 1 ft is approximately 0.305 m. How many meters are there in a mile? How many kilometers (km) are there in a mile?

## I need to know steps please^^

##### 1 Answer
Aug 29, 2017

1 mile is equal to 1610 meters and 1.610 km.

#### Explanation:

The method I learned, and still use, for unit conversion is to multiply by 1 in such a way that the existing unit is canceled and the desired unit survives.

The principle is to make use of the facts that
$\frac{a}{b} = 1$ if $a = b$
and that you can multiply anything by 1 without changing its value.

Consider the US dollar.
1 dollar = 100 pennies.

Therefore
$\left(1 \text{ dollar") / (100" pennies}\right) = 1$ and $\left(100 \text{ pennies")/ (1" dollar}\right) = 1$
Note: There are 2 fractions, both shown to be equal to 1, because you will have to choose which way is needed for the cancellation to work the way you need it to work.

Example converting \$5.25 to pennies:
5.25 cancel(" dollars") * (100 " pennies")/ (1 cancel(" dollar")) = 525 " pennies"

This is the conversion from miles to meters:
1 cancel("mile") * (5280 cancel(ft))/(1 cancel("mile")) * 0.305 m/(1 cancel(ft)) = 5280*0.305 m = "1610 meters"

This is the conversion from miles to km:
1 cancel("mile") * (5280 cancel(ft))/(1 cancel("mile")) * (0.305 cancel(m))/(1 cancel(ft))* (1 km)/(1000 cancel(m)) = (5280*0.305)/1000 km = "1.610 km"

I hope this helps,
Steve