What's the procedure for working out multiplying fractions?

To multiply a natural number by a fraction (or vice versa), we multiply the numerator by that number, and leave the denominator unchanged.

If we want to multiply two fractions, multiply the numerator of the first fraction by the numerator and denominator of the second fraction by the denominator of the first second.

During multiplication, if possible fractional shortening can be used. Be sure to shortening always choose one number from the counter, the other from the denominator.

If we want to multiply two numbers mixed, both replace for improper fractions and multiply the numerator by numerator and denominator by the denominator.

Multiplying fractions is commutative and cumulative.