Multiplying Fractions

Multiplying Fractions :

When multiplying by a fraction, multiply numerators and multiply denominators, if possible,reduce it to the lowest fraction.

Example : Some more examples :

1) 5/8 x 7/5

Solution :

First multiply numerators (top numbers) and then multiply bottom numbers.

5/8 x 7/5 = ( 5 x 7)/(8 x 5)

= 35/40

Now write the fraction in lowest form.

As both the numbers are divisible by 5.

So, (35 ÷5)/( 40 ÷ 5)

= 7/8

2) 11/4 x 3/7

Solution:

11/4 x 3/7 = (11 x 3)/(4 x 7)

= 33/28

As both the numbers are not divisible by any common number

So, 11/4 x 3/7 = 33/28

Application on product of fractions :

1) Tara is using boards and cement blocks to make shelves for her dorm room. Each shelf uses ½ of a board and 2 cement blocks. If Tara has 7 boards and 16 cement blocks, how many shelves can she make?

Solution :

Number of boards =7

Required board for one shelf = 1/2

So total boards we have = 14 (half boards)(7 x 2/1=14)

Number of cement blocks = 16

Required cement blocks =2

See the diagram In this way number of shelves = 8
(calculation) Number of shelves = (14 + 2)/2 = 16/2 = 8

2) What is one-third of two-fifth?

Solution :
One-third = 1/3
two-fifth = 2/5
So, 1/3 of 2/5 = 1/3 x 2/5
= (1 x 2)/(3 x 5)
= 2/15

3) What is one-half of one dozen mango?

Solution :
One-half = 1/2
one dozen mango = 12 mangoes
So, 1/2 of 12 = 12/2
= 6 mangoes

Fraction

Types of Fractions
Conversion of improper to mixed fraction
Equivalent Fractions
Fractions in Simplest form
Like and Unlike Fractions