Question

In your own words explain why you need to first find the common denominator when adding/subtracting fractions and you do not need to find a common denominator when multiplying/division fractions, ie why don’t you need to find a common denominator when multiplying/dividing fractions?

Answer 1

You need a common denominator while subtracting because really a fraction is a division problem and you cannot do 4/5-8/9 it does not make sense as for multiplication you really just multiplying everything that is why it makes sense.