Simplifying a ratio works the same way as simplifying a fraction.

If you had the fraction 63/147, you would look for common factors to divide by. You might first try 3, and find that 63÷3 =

**21** and 147÷3 =

**49**, so the fraction is equal to

**21/49**. Then you might realize that both of these numbers can be divided by 7, so you find that 21÷7 =

**3** and 49÷7 =

**7**, resulting in the fraction

**3/7**.

Or, if you're insightful, you might just think of dividing by 21 all at once, rather than 3 and then 7. The result is that 63:147 = (63÷21)

147÷21) = 3:7.