The easiest way to reduce big fractions is by seeing if both numbers are divisible by the same number. If it is, you can divide both numbers by that number.
When you do this, it is easier to start with small prime numbers such as 2, 3, and 5.
you have to find the GCF of the numerator and the denominator but if it does not share the same GCF then there is no other way you can reduce the fraction
