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Comparing Fractions Made Simple for Students

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How to Compare Fractions with Unlike Denominators and Examples

By comparing fractions, we mean determining which is the larger and which is the smaller fraction. Numerators and denominators of fractions are compared using a set of rules because they are composed of two parts. Let us learn more about comparing fractions on this page. The numerator is the number on the upper part of the fractional bar that tells how many pieces of the whole we're talking about. The denominator is located below the fractional bar that tells how many total pieces make up one whole. How do you compare fractions? In this article, we discuss the different methods of how to compare fractions to understand the concept better.


Fractions

Fractions


Fractions

A fraction can be expressed in the form $\dfrac{a}{b}$, where a, and b are whole numbers and b≠0, in which ‘a‘ is the numerator and ‘b’ is the denominator.

The numbers like $\dfrac{3}{5}$, $\dfrac{2}{3}$, etc., are fractions.

Like and unlike fractions are the two groups of fractions:

  • Like Fractions - Fractions with the same denominator.

Example: $\dfrac{1}{7}$, $\dfrac{2}{7}$, $\dfrac{3}{7}$

The denominator of each fraction is the same i.e., 7.

  • Unlike Fractions - Fractions with different denominators.

Example: $\dfrac{1}{4}$, $\dfrac{5}{6}$, $\dfrac{1}{3}$

The denominator of each fraction is different.


Comparing Fractions

Finding the greater and smaller fraction between any two or more fractions is known as comparing fractions. Fractions are compared according to a set of rules. In this article, we study more about comparing fractions and comparing unlike fractions and their steps to compare fractions.


Ways of Comparing Fractions

A set of rules relating to the numerator and denominator must be followed while comparing fractions. We can find the greater and smaller fractions by comparing any two fractions. We compare fractions by comparing like fractions and comparing unlike fractions.


Comparing Fractions


Comparing Fractions


Methods of Comparing Fractions

  • Decimal Method

  • Same Denominator Method


Comparing Fractions with Unlike Denominators

For comparing fractions with unlike denominators, we must convert fractions from different denominators to similar denominators. For this, we must find the Least Common Multiple(LCM) for the denominators. Then we easily compare the fractions.


Comparing Unlike Fractions

Comparing Unlike Fractions


Method 1: Decimal Method of Comparing Fractions with Different Denominators

This method compares fractional decimal numbers. For this, the fraction is reduced to a decimal form by dividing the numerator by the denominator. The decimal values are then compared. Let's compare $\dfrac{2}{5}$ and $\dfrac{5}{8}$ as an example. These are the following steps to compare fractions:

  • Step 1: Write the numbers $\dfrac{2}{5}$ and $\dfrac{5}{8}$ in decimals.

$\dfrac{2}{5}$ = 0.4

$\dfrac{5}{8}$ = 0.625

  • Step 2: Evaluate the decimal values. 0.625 > 0.4

  • Step 3: The fraction that has a higher decimal value is greater. Hence, $\dfrac{5}{8}$ > $\dfrac{2}{5}$.


Method 2: Same Denominator Method of Comparing Fractions with Unlike Denominators

For comparing fractions with unlike denominators, the Least Common Multiple (LCM) of the denominators should be determined in order to convert them to like denominators. For example, compare $\dfrac{3}{4}$ and $\dfrac{2}{5}$. These are the following steps of the same denominator method:

  • Step 1: Check the fractions' denominators, 4 and 5. They are different.

Thus, LCM(4 and 5) = 20.

  • Step 2: Now convert their denominators to the same. Multiply the first fraction by $\dfrac{5}{5}$, and the second fraction by $\dfrac{4}{4}$,

i.e., $\dfrac{3}{4} \times \dfrac{5}{5}$ = $\dfrac{15}{20}$

$\dfrac{2}{5} \times \dfrac{4}{4}$ = $\dfrac{8}{20}$

  • Step 3: Compare the fractions $\dfrac{15}{20}$ and $\dfrac{8}{20}$. We will compare the numerators because the denominators are the same, so 15 > 8.

  • Step 4: The greater fraction is the fraction with the larger numerator, $\dfrac{15}{20}$ > $\dfrac{8}{20}$

So, $\dfrac{3}{4}$ > $\dfrac{2}{5}$.

We can simply compare fractions by looking at their denominators if the denominators are different and the numerators are the same. Fractions with a greater denominator have a lesser value, while fractions with a smaller denominator have a greater value. For example, $\dfrac{2}{3} > \dfrac{2}{6}$


Solved Examples

Q1. Which is larger, $\dfrac{7}{12}$ or $\dfrac{4}{15}$ ?

Ans: The LCM of the denominators 12 and 15.

$\operatorname{LCM}(12, 15)=2 \times 2 \times 3 \times 5=60$

Now, convert the fractions to equivalent fractions with a denominator of 60.

$\dfrac{7}{12}=\dfrac{(7 \times 5)}{(12 \times 5)}=\dfrac{35}{60}$

$\dfrac{4}{15}=\dfrac{(4 \times 4)}{(15 \times 4)}=\dfrac{16}{60}$

Now, observe the numerator, $35>16$.

So, $\dfrac{35}{60}$>$\dfrac{16}{60}$

Therefore, $\dfrac{7}{12}$>$\dfrac{4}{15}$.


Q2. Compare $\dfrac{9}{10}$ and $\dfrac{9}{6}$ with the decimal method.

Ans: First write the fractions in decimals form.

$\dfrac{9}{10}$ = 0.9

$\dfrac{9}{6}$ = 1.5

The fraction that has a higher decimal value is greater. hence, $\dfrac{9}{6}$ > $\dfrac{9}{10}$.


Q3. Shalu has $\dfrac{3}{5}$ of her homework complete and Malini has $\dfrac{3}{4}$ of her homework complete. Who has done more homework?

Ans: The LCM of the denominators 5 and 4 is 20.

Now, convert fractions to equivalent fractions with a denominator of 20.

$\dfrac{3}{5} = \dfrac{(3 \times 4)}{(5 \times 4)} = \dfrac{12}{20}$

$\dfrac{3}{4} = \dfrac{(3 \times 5)}{(4 \times 5)} = \dfrac{15}{20}$

So, $\dfrac{15}{20}$ > $\dfrac{12}{20}$

Therefore, $\dfrac{3}{4}$ > $\dfrac{3}{5}$.


Practice Questions

Q1. Compare $\dfrac{3}{8}$ and $\dfrac{8}{9}$ which is greater?

Ans: $\dfrac{8}{9}$


Q2. Arrange the fractions $\dfrac{5}{4}$, $\dfrac{7}{4}$, $\dfrac{2}{9}$, and $\dfrac{5}{8}$ in Ascending order.

Ans: $\dfrac{2}{9}$, $\dfrac{5}{8}$, $\dfrac{5}{4}$, $\dfrac{7}{4}$


Q3. Rajni ate $\dfrac{9}{22}$ part of the pizza and Irfan ate $\dfrac{5}{11}$ part of the pizza. Who ate the greater part of the pizza?

Ans: Irfan ate the greater part of the pizza.


Q4. Jasmine covered a distance of $\dfrac{9}{11}$ km and Madhav covered a distance of $\dfrac{5}{7}$ km. Who covered the greater distance?

Ans: Madhav covered the greater distance.


Summary

In this article, we got to know about comparing fractions. Here we specifically learned about comparing unlike fractions with two different methods, the decimal method, and the same denominator method. You can compare two fractions with unlike denominators by comparing their denominators’ LCM. By comparing fractions, we identify which part is larger and which part is smaller. So, comparing fractions is a very important and regular part of our life.

FAQs on Comparing Fractions Made Simple for Students

1. What does comparing fractions mean?

Comparing fractions means deciding which fraction is greater than, less than, or equal to another fraction. When comparing fractions, you are checking their numerical value on a number line.

  • If two fractions have the same denominator, compare the numerators.
  • If two fractions have the same numerator, compare the denominators.
  • If they are different, use a common denominator or cross-multiplication.
For example, between 3/4 and 2/4, 3/4 is greater because 3 > 2.

2. How do you compare fractions with the same denominator?

To compare fractions with the same denominator, compare their numerators; the fraction with the larger numerator is greater. Since the parts are equal in size, more parts mean a larger value.

  • Example: Compare 5/8 and 3/8.
  • Both have denominator 8.
  • Since 5 > 3, 5/8 > 3/8.
This method works because the whole is divided into the same number of equal parts.

3. How do you compare fractions with the same numerator?

To compare fractions with the same numerator, the fraction with the smaller denominator is greater. A smaller denominator means each part is larger.

  • Example: Compare 3/5 and 3/7.
  • Both have numerator 3.
  • Since 5 < 7, 3/5 > 3/7.
This is because fifths are larger pieces than sevenths.

4. How do you compare fractions with different denominators?

To compare fractions with different denominators, convert them to a common denominator or use cross-multiplication. These methods make the fractions easier to compare.

  • Example: Compare 2/3 and 3/4.
  • Cross-multiply: 2 × 4 = 8 and 3 × 3 = 9.
  • Since 8 < 9, 2/3 < 3/4.
You can also convert them to twelfths: 8/12 and 9/12.

5. What is the cross-multiplication method for comparing fractions?

The cross-multiplication method compares fractions by multiplying each numerator by the opposite denominator and comparing the results. It works for any two fractions.

  • For a/b and c/d, compare a × d and b × c.
  • If a × d > b × c, then a/b > c/d.
Example: Compare 5/6 and 4/5.
  • 5 × 5 = 25
  • 6 × 4 = 24
  • Since 25 > 24, 5/6 > 4/5.

6. How do you compare mixed fractions?

To compare mixed fractions, first compare the whole numbers, then compare the fractional parts if needed. The larger whole number means the larger mixed number.

  • Example: Compare 2 1/3 and 1 5/6.
  • Since 2 > 1, 2 1/3 > 1 5/6.
If whole numbers are equal, compare the fractions using a common denominator or cross-multiplication.

7. How do you compare fractions using a number line?

To compare fractions on a number line, the fraction placed further to the right is greater. A number line visually shows the size of each fraction.

  • Divide the line into equal parts based on the denominator.
  • Mark each fraction correctly.
  • The fraction farther right has the larger value.
For example, 3/4 is to the right of 1/2, so 3/4 > 1/2.

8. What is the least common denominator when comparing fractions?

The least common denominator (LCD) is the smallest common multiple of the denominators used to rewrite fractions for easy comparison. It helps convert fractions into equivalent forms.

  • Example: Compare 1/6 and 1/8.
  • LCM of 6 and 8 is 24.
  • 1/6 = 4/24 and 1/8 = 3/24.
  • Since 4/24 > 3/24, 1/6 > 1/8.

9. How do you compare improper fractions?

To compare improper fractions, use cross-multiplication or convert them to mixed numbers for easier understanding. The method is the same as for proper fractions.

  • Example: Compare 7/4 and 9/5.
  • 7 × 5 = 35 and 4 × 9 = 36.
  • Since 35 < 36, 7/4 < 9/5.
You may also convert them: 7/4 = 1 3/4 and 9/5 = 1 4/5.

10. What are common mistakes when comparing fractions?

A common mistake when comparing fractions is comparing only the numerators or denominators without checking if they are the same. This can lead to incorrect conclusions.

  • Do not assume 1/8 > 1/6 just because 8 > 6.
  • Always check if denominators are equal before comparing numerators.
  • Use a common denominator or cross-multiplication when needed.
For example, since sixths are larger than eighths, 1/6 > 1/8.