Real life applications where common fractions are multiplied or divided include:
Steps to multiply fractions are:
The extra step to divide fractions is to multiply by the reciprocal of the second fraction (that is, turn the second fraction upside and then multiply).
An image is reduced to one half of its original size. If the original measurement is 3⁄4 cm, what is the new reduced measurement?
Answer:
1⁄2 × 3⁄4
= 3⁄8 cm
A risotto recipe for 5 people uses 2 1⁄2 cups of rice. How many cups of rice are required to feed 20 people?
Answer:
Multiplier
= 20 ÷ 5
= 4
No. of cups of rice
= 2 1⁄2 × 4
= 10 cups
Q1. 1⁄3 × 2⁄5
Q2. 3⁄8 × 4⁄5
Q3. 2 1⁄4 × 3 2⁄3
Answers
A1. 2⁄15
A2. 3⁄10
A3. 8 1⁄4
In a gym the whole 2 1⁄2 hour training session is divided into 1⁄4 hour parts. How many parts is this?
Answer:
2 1⁄2 ÷ 1⁄4
= 5⁄2 ÷ 1⁄4
= 5⁄2 × 4⁄1
= 20⁄2
= 10 parts
Q1. 6⁄7 ÷ 1⁄4
Q2. 3⁄8 ÷ 1⁄2
Q3. 2 4⁄5 ÷ 1⁄10
Answers
A1. 3 3⁄7
A2. 3⁄4
A3. 28