As you saw in the clip, if both numbers are multiples of 10, just divide by 10! d
If both are multiples of another number, like 7 or 5, divide the numerator and denominator by that to write the equivalent, simplified fraction.
If you're not sure, try dividing them using short division to check if they are divisible by 3, 4, 5, etc. or something else.
If the numbers are even, you can just keep halving them to simplify too (until one of them becomes odd, then you might need to divide by 3 or 5 or something else if possible).