# How to Convert Units Interactive

Let's say we have a \$5 bill and we need to know how many quarters that is, How do we convert our unit of \$5 bill into the unit of a quarter.

We need to find the conversion factor. To find the conversion factor, all we need is to find how many quarters are in a \$5 bill.
there are 4 quarters in \$1 and a \$5 bill is worth \$1 * 5, so our conversion factor is (20 quarters)/(\$5 bill).

Our conversion factor will always equal 1.
Why? Because when we convert from one unit to another we are not changing the value!
We are only changing how the value is represented.
Therefore, our conversion factor must be 1 because multiplying by any other number will change our value.
Now that we have found our conversion factor, all we do is multiply it to our \$5 bill (\$5 bill) * (20 quarters)/(\$5 bill) = 20 quarters;

Let's see if we can get the idea below.

### Key Takeaways

We convert units all the time, often without thinking about it. We convert units with money, with time, and we certainly convert units in Mathematics.

The most well-known example is Degrees to Radians or vice versa.
However, it doesn't matter what units we convert, the process is always the same.
We find the conversion factor by finding a fraction of our units that is equal to 1, in this case (180°/π ) or (π/180°) because π = 180°.

We want our desired unit on top and the unit we are converting from on the bottom.
We can think of this as multiplying in our new unit and dividing out our old unit.

Then all we have to do is multiply and we are done, we have our value expressed in our new unit.

Finding the conversion factor is normally the hardest part. Everything else is simple.

Most of all, we must remember, we are not changing the value. We are just changing the unit.