What a fraction is and what the types of fractions are, have been explained in detail in the chapter Fractions Types, Representation With Diagrams And Conversions. Methods to compare fractions depend upon the type of fractions. The types of fractions can be like fractions or unlike fractions.
Like fractions are the fractions which have the same denominator and unlike fractions are the fractions with different denominators.
This chapter explains the steps of comparison of two or more than two fractions. This comparison helps in finding which fractions is the biggest and the smallest. After comparing, the fractions can be written in ascending order or descending order.
Comparing like fractions
Like fractions have the same denominator. So, while making comparisons of like fractions, the comparison is made on the basis of only the numerator leaving the denominator as it is. The numerators of all fractions are compared in the same way as the normal numbers are compared.
Greater the numerator, greater will be the fraction. Smaller the numerator, smaller the fraction will be.
Compare fractions and
As these two fractions have the same denominators as 5, so this is an example of like fractions. So, in the case of like fractions, only numerators will be compared leaving denominators aside.
Here, the numerators are 16 and 11 in and respectively.
So, we can say 16 is greater than 11.
Therefore, fraction with numerator 16 will also be greater than the fraction with numerator 11.
∴ is greater than
Compare fractions
and fractions have the same denominators as 4.
So, only numerators will be compared as these are like fractions.
The numerators of and fractions are 11, 21 and 9.
So, 21 is the largest number followed by 11 and then 9.
It can be written as 9 < 11 < 21.
So, the fractions can be written as
Comparing unlike fractions
Unlike fractions have different denominators and their numerators may or may not be the same.
and
and
While making comparisons of unlike fractions, the denominator is compared only among the fractions. Again, the denominators are compared the same as the normal numbers are compared. So, greater the denominator, smaller will be the fraction. Smaller the denominator, greater the fraction will be.
There are two methods that can be used to compare unlike fractions. The both methods differ depending upon whether the numerator is the same or different. Let's see how these two types of unlike fractions are compared.
Same numerator
To compare the unlike fractions with the same numerator, the denominator of each fraction is compared. The fraction with smaller denominator is greater than the other fraction which has greater denominator.
In other way around, the fraction with greater denominator is smaller than the other fraction which has smaller denominator
Compare fractions and
and are unlike fractions with the same numerator.
So, only denominators 5 and 8 will be compared.
We can say, 8 > 5
Therefore,
Or is less than
Or is greater than
Compare fractions and
The numerator in both fractions is the same, so compare denominators 5 and 6 only.
We can say, 6 > 5
Therefore,
Or,
Different numerator
To compare the unlike fractions with different denominators, first unlike fractions are converted into like fractions using LCM.
- Take the LCM of denominators of all fractions.
- Then multiply the numerator and denominator of every fraction with such a number that makes the denominator equal to the number obtained in LCM.
Compare fractions and
To compare unlike fractions with different denominators 3 and 5, first take LCM of 3 and 5.
LCM of 3 and 5 = 15
Now multiply by 5 and by 3 to make their denominators equal to LCM 15.
and
Hence, in both fractions, now the denominators are equal to LCM 15. As both fractions have the same denominators which is 15, now they can be compared using numerator only.
So, 20 > 6
∴
i.e.
Comparing unit fractions
Unit fractions are the fractions with value of numerator as one and denominator can be any positive integer.
,
In other words, unit fractions are unlike fractions where the numerator is always the same i.e. one and the denominator is different. Therefore, unit fractions can be compared with one of the above methods used in comparing unlike fractions with the same numerator.
As we have already seen above, this method uses only denominators to compare the fractions. A fraction with greater denominator is smaller in unit fraction and a fraction with smaller denominator will be greater in unit fraction.
Compare fractions and
Fractions and are unit fractions with denominators 5 and 7 respectively.
Unit fractions are compared by finding the greatest denominator, so denominator 7 is greater than 5.
∴
Cross multiplication method
In cross multiplication method to compare unlike fractions with different numerators, fractions are cross multiplied. Then the two values obtained after the multiplication are compared to check which fraction is greater or smaller.
Cross multiplication method is limited to compare maximum two fractions only.
Cross multiplication method can be used to compare any two fractions whether they are unit fractions, like fractions or even unlike fractions.
Compare unit fractions and
Cross multiply both fractions

So, 1 × 7 = 7 and 1 × 5 = 5
So, 7 > 5
Compare like fractions and
Cross multiply both fractions

So, 16 × 5 = 80 and 11 × 5 = 55
So, 80 > 55
Compare unlike fractions and
Cross multiply both fractions

So, 4 × 5 = 20 and 3 × 2 = 6
So, 20 > 6
Ordering of fractions
Ordering of fractions are meant by arranging the fractions in ascending order or descending order. Fractions can be written in an order after the comparison of fractions are completed.
Let's see with the following examples how the like fractions, the unlike fractions with same numerator and the unlike fractions with different numerators can be arranged.
Like fractions
Ordering of like fractions can be done after the fractions have been compared using the method described in comparing like fractions, which compares the numerator only.
Write in ascending order.
The fractions and are like fractions as each fraction has the same denominator.
So, compare their numerator.
1 < 3 < 4 < 6 < 7
Or we can write fractions in the ascending order as:
and
∴ Descending order of fractions can be written as:
and .
Unlike fractions (same numerators)
Ordering of unlike fractions with the same numerator is done after doing their comparison.
Arrange unlike fractions in ascending order.
Compare the denominator as all fractions have the same numerator i.e. 4.
The fraction with smaller denominator is greater for unlike fractions.
The denominators in ascending order 3 < 5 < 6 < 7 < 9
3 is the smallest and 9 is the largest denominator.
Therefore, the fraction with denominator 3 will be the greatest fraction.
∴ descending order can be written as
Ascending order will be the reverse
Unlike fractions (different numerators)
Ordering of unlike fractions with different numerators is done after doing their comparison.
To arrange the unlike fractions with different numerators in ascending order or descending order, first change unlike fractions into like fractions. Take LCM of all denominators, then multiply each fraction with the LCM to make the denominators same for all fractions.
Arrange fractions into ascending order.
These fractions are unlike fractions with different numerators.
Take the LCM of denominators of all fractions i.e. 3, 4, 2, 5 and 4
LCM of 3, 4, 2, 5 and 4 = 60
Multiply each fraction with the number to get the required LCM 60.
These fractions become like fractions with the same denominator of 60 and now compare their numerator.
15 < 30 < 80 < 84 < 150
Or
Therefore, these fractions can be arranged in ascending order as:
Also, these fractions can be arranged in descending order as:
