Finding a Fraction of a Whole Number

How to find a fraction of a whole number?

For finding a fraction of a whole number, we multiply the numerator of the fraction by the given number and then divide the product by the denominator of the fraction.

Solved examples for finding a fraction of a whole number:

(i) Find \(\frac{1}{3}\) of 21.

To find \(\frac{1}{3}\) of 21, we multiply the numerator 1 by the given whole number 21 and then divide the product 21 by the denominator 3.

\(\frac{1}{3}\) × 21 = \(\frac{1 × 21}{3}\) = \(\frac{21}{3}\) = 7

So, \(\frac{1}{3}\) of 21 = 7.

(ii) Find \(\frac{2}{5}\) of 15.

To find \(\frac{2}{5}\) of 15, we multiply the numerator 2 by the given whole number 15 and then divide the product 30 by the denominator 5.

\(\frac{2}{5}\) × 15 = \(\frac{2 × 15}{5}\) = \(\frac{30}{5}\) = 6

So, \(\frac{2}{5}\) of 15 = 6.

(iii) Find \(\frac{3}{8}\) of 48.

To find \(\frac{3}{8}\) of 48, we multiply the numerator 3 by the given whole number 48 and then divide the product 144 by the denominator 8.

\(\frac{3}{8}\) × 48 = \(\frac{3 × 48}{8}\) = \(\frac{144}{8}\) = 18

So, \(\frac{3}{8}\) of 48 = 18.

Finding Fractions:

To Find Half or One Half -

1. Ram has 20 biscuits. He wants to give half of them to his sister. How many should he give her?

Ram has to give 1 of 2 equal parts to his sister. So, to put the collection in two equal parts, divide it by two i.e. 20 ÷ 2 = 10.

Ram will give one part (10 biscuits) to his sister.

2. David gave his brother Matthew part of his chocolate bar.

Did Matthew get half the chocolate?

No, because we call one of two equal parts half. Equal means that the parts are of the same size.

This shape has two equal parts.

When a whole is divided into two equal parts, each part is called one half.

One of the two equal parts is blue we say that one-half is blue.

We write: \(\frac{1}{2}\) blue.

To Find One Third -

One third is 1 part of 3 equal parts.

9 ÷ 3 = 3 \(\frac{1}{3}\) of 9 is 3.

To put a collection in three equal parts, divide it by three.

One part of it is \(\frac{1}{3}\).

When a whole is divided into three equal parts, each part is called one-third.

One of the three parts is blue.

We say: One-third is blue.

We write: \(\frac{1}{3}\) is blue.

Two of the three parts are yellow.

We say: Two-thirds is yellow.

We write: \(\frac{2}{3}\) is yellow.

To Find One Fourth -

One fourth is I part of 4 equal parts.

8 ÷ 4 = 2 \(\frac{1}{4}\) of 8 is 2.

To put a collection in four equal parts, divide it by four.

One part of its is \(\frac{1}{4}\).

When a whole is divided into four equal parts, each part is called one-fourth.

One of the four parts is green.

We say: One-fourth is green.

We write: \(\frac{1}{4}\) is green.

Two of the four parts are green.

We say: Two-fourths is green.

We write: \(\frac{2}{4}\) is green.

Three of the four parts are green.

We say: Three-fourths is green.

We write: \(\frac{3}{4}\) is green.

Story Sums on Finding a Fraction of a Whole Number:

1. There are 10 children in a classroom. If half of them were boys then how many girls were there?

Answer: 5

2. Neetu had 8 toffees. She ate half of them. How is she left with now?

Answer: 4

3. Amit had 6 balloons. One third of the balloons burst. How many balloons are left?

Answer: 4

4. Sita had 24 biscuits. She gave one fourth to her mother. How many biscuits were left?

Answer: 18

5. 10 friends shared 5 cold drinks. What fraction of cold drink did each friend get?

Answer: \(\frac{5}{10}\) or \(\frac{1}{2}\)

6. Neeta bought 5 chocolates. She eats 3 of them. What fraction of the chocolates did she eat?

Answer: \(\frac{3}{5}\)

7. There were nine flower pots in Aman's garden. 4 pots fell down. What fraction of pots are left in his garden. 

Answer: \(\frac{5}{9}\)

Related Concept

● Fraction of a Whole Numbers

● Representation of a Fraction

● Equivalent Fractions

● Properties of Equivalent Fractions

● Like and Unlike Fractions

● Comparison of Like Fractions

● Comparison of Fractions having the same Numerator

● Types of Fractions

● Changing Fractions

● Conversion of Fractions into Fractions having Same Denominator

● Conversion of a Fraction into its Smallest and Simplest Form

● Addition of Fractions having the Same Denominator

● Subtraction of Fractions having the Same Denominator

● Addition and Subtraction of Fractions on the Fraction Number Line

4th Grade Math Activities

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