When multiplying fractions, you can cross-cancel common factors, and then multiply numerator by numerator, and denominator by denominator. You don’t necessarily need to cross-cancel common factors but it simplifies the problem for you.
Alternatively, we could cancel the 2 at the top of the 1st term, and the 2 at the bottom of the 2nd term, since . Thus, we have
We reach the same answer, but cancelling is easier if you have very large numbers, or you will take forever to simplify.
Multiplying mixed numbers
When multiplying mixed numbers, it is necessary to convert them first to improper fractions, and then multiply.
To divide by a fraction, you multiply by its reciprocal (i.e. inverted, such that for the dividing fraction, put the top on the bottom, and the bottom on the top).
Dividing mixed numbers
When dividing mixed numbers, first convert to improper fractions, and then divide (i.e. multiply by the reciprocal).