Learning Math Can Be Fun: Multiplying Fractions

Multiplying Fractions

A basic property of multiplying fractions is analogous to the additive inverse property that can be taken as the extension of whole numbers to integers. Multiplication by fractions can then be defined in the light of the associative and commutative properties; multiplication by 1/n is equivalent to multiplication by 1 followed by division by n: for example 0.3 ✕ 0.7 = 0.3 ✕ 7/10 = (0.3 ✕ 7)/10 = 2.1/10 = 0.21

I would like to share some ideas of the procedures of multiplying fractions.

Multiplying Fractions

To Multiply Fractions:

· Multiply the numerators of the fractions

· Multiply the denominators of the fractions

· Place the product of the numerators over the product of the denominators

· Simplify the Fraction

Example: Multiply 2/9 and 3/12

· Multiply the numerators (2*3=6)

· Multiply the denominators (9*12=108)

· Place the product of the numerators over the product of the denominators (6/108)

· Simplify the Fraction (6/108 = 1/18)
The Easy Way. It is often simplest to "cancel" before doing the multiplication. Canceling is dividing one factor of the numerator and one factor of the denominator by the same number.

· For example: 2/9 * 3/12 = (2*3)/(9*12) = (1*3)/(9*6) = (1*1)/(3*6) = 1/1