Last updated on July 4th, 2025
When we are multiplying a fraction with a whole number, we first convert the whole number into a fraction. We convert a whole number into a fraction by placing 1 as the denominator. Now, we apply the regular rules for multiplying fractions and whole numbers. Let us understand more about it along with some examples.
Fraction is a way of representing a part of a whole or a portion of something. For example, there is pizza divided into 4 equal parts. If you eat 1 slice, you have eaten 1/4 of the pizza. Here 1 is the numerator which tells us how many parts you have. 4 is the denominator and tells us how many equal parts the whole is divided into.
Whole numbers are the natural numbers, along with zero. The set of whole numbers is 0, 1, 2, … The difference between natural and whole numbers is that whole numbers include 0, while natural numbers begin from 1.
Multiplying fractions by whole numbers is similar to adding the same fraction repeatedly. Where the fraction is added as many times as the whole number indicates. To multiply the fractions, we multiply the numerators together and the denominators together, and then simplify the result if needed. If we are multiplying the fraction by a whole number, we first write that whole number as a fraction by putting 1 over it. Then we use the multiplication rule that is a/b × c/d gives (a × c )/(b × d). The same rule works when multiplying fractions with whole numbers.
To multiply mixed fractions, we first need to convert those mixed fractions to an improper fraction. After converting it to improper fraction, follow these steps to multiply:
Step 1: Convert the mixed fraction into an improper fraction.
Step 2: Convert a whole number into a fraction by placing 1 over it.
Step 3: Multiply the numerators.
Step 4: Multiply the denominators.
Step 5: Simplify the result if needed.
For example, multiply 1 1/6 x 5
Children often make some mistakes when they are multiplying fractions with whole numbers. Here are some common mistakes children often make and some strategies on how to avoid them.
Multiply 1/2 x 4
4/1
1 × 4 = 4
2 × 1 = 2
4/2 = 2
First write the whole number into a fraction which is 4/1. Now multiply both the numerators and denominators, and then we get 4/2. If we simplify, we get 2 as the result.
Each plant in the garden requires 2/3 gallon of water. If there are 9 plants, how much water is needed?
2/3 x 9
Convert whole number into fraction: 9/1
Multiply the numerators: 2 × 9 = 18
Multiply the denominators: 3 × 1 = 3
18/3 = 6.
Each plant needs ⅔ gallon of water, so multiply ⅔ by 9 to get the final result. This gives 18/3. If we simplify the answer we get the final result as 6. So 6 gallons of water is needed.
A piece of wood is 2/5 meter long. If you need 15 pieces of wood to build a fence, what is the total length of wood required ?
2/5 x 15
Convert whole number into fraction:15/1
Multiply the numerators: 2 × 15 = 30
Multiply the denominators: 5 × 1 = 5
30/5 = 6.
To find the length of wood we needed, multiply the length of one piece which is 2/5 meter by the total number of pieces which is 15. It gives us a total of 30/5. The final result is 6 meters.
7/10 x 5
7/10 x 5
Convert whole number into fraction: 5/1
Multiply the numerators: 7 × 5 = 35
Multiply the denominators: 1 × 10 = 10
35/10 = 7/2
To multiply 7/10 by 5, first write the whole number 5 into a fraction: 5/1. Then multiply the numerators and denominators of both the fractions. We get the result as 35/10, which simplifies to 7/2.
Multiply 3/5 x 10
3/5 x 10
Convert whole number into fraction: 10/1
Multiply the numerators: 3 × 10 = 30
Multiply the denominators: 5 × 1 = 5
30/5 = 6
First, convert the whole number to a fraction, and then multiply the numerators and denominators of the two fractions. Divide the final result with the Greatest Common Factor of both the numerator and the denominator. The final answer is 6.
Hiralee Lalitkumar Makwana has almost two years of teaching experience. She is a number ninja as she loves numbers. Her interest in numbers can be seen in the way she cracks math puzzles and hidden patterns.
: She loves to read number jokes and games.