Grade 5 ↓
Fractions
Fractions are a way of representing parts of a whole. When we talk about fractions, we are discussing how many parts of a certain size there are in something. Fractions can be used in many everyday situations, such as cooking, dividing a pizza, reading a clock, and much more.
What is fraction?
In the simplest sense, a fraction is a number that represents a part of a whole. It is used to show how many parts we have out of a certain number of equal parts. A fraction is made up of two main components: the numerator and the denominator.
Fraction example: Let's look at the fraction 3/4
. Here, 3 is the numerator, and 4 is the denominator.
Meter
The numerator is the top number in a fraction. It tells us how many parts we have. In the fraction 3/4
, the number 3 is the numerator. This means we have 3 parts.
Divisor
The denominator is the bottom number in a fraction. It tells us how many equal parts the whole number is divided into. In the fraction 3/4
, the number 4 is the denominator. This means the whole number is divided into 4 equal parts.
Fraction table:
Whole | Parts taken | Fractions 1 | 1 | 1/1 1 | 2 | 1/2 1 | 3 | 1/3 1 | 4 | 1/4 1 | 5 | 1/5
Reading and writing fractions
When writing or reading fractions we usually say the numerator first and then the denominator. For example:
1/2
is read as "half."3/4
is read "three quarters."5/8
is read as "five eighths."7/10
is read "seven tenths".
Visualization of fractions
Fractions are easier to understand when we can visualize them. Below is an example of a pie chart representation of the fraction 1/4
.
In this circle, the shaded area represents 1/4
of the whole.
Similarly, we can represent other fractions also using visual charts.
Equivalent fractions
Sometimes, different fractions can represent the same quantity. Such fractions are called equivalent fractions. For example, 1/2
is equal to 2/4
, 3/6
or 4/8
. They all mean the same thing.
Example of equivalent fractions:
1/2 = 2/4 = 3/6 = 4/8 Each of these fractions is equivalent. They all represent the same part of a whole.
Comparing fractions
We often have to compare fractions to find out which fraction is bigger and which is smaller. There are several ways we can do this.
Method 1: Common denominator
The primary method of comparing two fractions is to change them to a common denominator. Once the denominators are the same, we can compare the numerators directly.
Example of comparing fractions:
Let's compare 2/3
and 3/4
. We can find a common denominator of 12:
2/3 = 8/12 (Multiply both numerator and denominator by 4) 3/4 = 9/12 (Multiply both numerator and denominator by 3) Now compare: 8/12 < 9/12. Therefore, 2/3 < 3/4.
Method 2: Cross-multiplying
Another method is cross-multiplication. Multiply the numerator of each fraction by the denominator of the other fraction.
Example of cross-multiplication:
Compare 1/3
and 2/5
:
1 * 5 = 5 2 * 3 = 6 Since 5 < 6, we conclude that 1/3 < 2/5.
Adding and subtracting fractions
Adding or subtracting fractions requires a common denominator. With the same denominator, you add or subtract fractions.
Adding fractions with the same denominators
Example of adding fractions: 1/4 + 2/4
1/4 + 2/4 = (1+2)/4 = 3/4
Subtracting fractions with the same denominators
Example of subtracting fractions: 3/5 - 1/5
3/5 - 1/5 = (3-1)/5 = 2/5
Adding or subtracting fractions with different denominators
Example: Add 1/2
and 2/3
.
Find a common denominator: lcm(2, 3) = 6 1/2 = 3/6 2/3 = 4/6 so, 1/2 + 2/3 = 3/6 + 4/6 = 7/6 or 1 1/6
Multiplication of fractions
Multiplying fractions is easier than adding or subtracting. You just multiply the numerators and multiply the denominators.
Example of multiplying fractions: 2/3
and 3/5
(2/3) * (3/5) = (2*3) / (3*5) = 6/15 = 2/5 (after simplification)
Division of fractions
To divide a fraction by another fraction, the first fraction has to be multiplied by the reciprocal of the second fraction.
Example of dividing fractions: divide 4/5
by 2/3
4/5 ÷ 2/3 = 4/5 * 3/2 = (4*3) / (5*2) = 12/10 = 6/5 or 1 1/5 (after simplification)
Converting improper fractions and mixed numbers
An improper fraction is a fraction in which the numerator is greater than or equal to the denominator. A mixed number contains a whole number and a fraction. They can be converted from one to the other.
Conversion example: Convert 7/4
to a mixed number.
7/4 = 1 3/4 1 full part + 3 parts of 4
Conversely, convert a mixed number to an improper fraction:
Example: Convert 1 1/2
to an improper fraction.
1 1/2 = (1*2 + 1)/2 = 3/2
Conclusion
Fractions are a fundamental part of mathematics and provide a means of expressing parts of a whole in different ways. By understanding the various concepts related to fractions - including equivalent fractions, addition and subtraction, multiplication and division, and converting between improper fractions and mixed numbers - you can build a strong foundation for tackling more complex mathematical ideas in the future.