Comparing fractions can seem tricky at first, but with a few methods, it becomes much easier. Here’s a step-by-step guide on how to compare fractions and determine which one is bigger:
1. Same Denominator
When two fractions have the same denominator, comparing them is straightforward. You just need to compare the numerators.
Example:
Compare 3/7 and 5/7.
Since both fractions have the same denominator (7), look at the numerators:
- 3/7 has a numerator of 3.
- 5/7 has a numerator of 5.
Since 5 is greater than 3, 5/7 fraction is larger than 3/7.
2. Different Denominators
When the fractions have different denominators, you need to find a common denominator to compare them. Here’s how to do it:
a. Find the Least Common Denominator (LCD):
The least common denominator is the smallest number that both denominators can divide into without leaving a remainder.
Example:
Compare 2/5 and 3/4.
- Find the LCD:
- The denominators are 5 and 4.
- The smallest number that both 5 and 4 divide into evenly is 20.
- Convert each fraction to have this common denominator:
- 2/5 is converted by multiplying the numerator and denominator by 4:2/5*4/4=8/20
- 3/4 is converted by multiplying the numerator and denominator by 5:3/4*5/5=15/20
- Compare the fractions:
- Now we have 8/20 and 15/20.
- Since 15 is greater than 8, 15/20 or (3/4) is larger than 8/20 or (2/5).
b. Cross-Multiplication:
An alternative way to compare fractions is to cross-multiply. This method avoids finding a common denominator.
Example:
Compare 2/7 and 3/5.
- Cross-multiply:
- Multiply the numerator of the first fraction by the denominator of the second fraction: 2×5=10 .
- Multiply the numerator of the second fraction by the denominator of the first fraction: 3×7=21.
- Compare the results:
- Since 10<21, 2/7 is less than 3/7.
3. Visual Method
You can also compare fractions by visualizing them with pie charts or fraction bars if you prefer a more intuitive approach. This is useful for a quick comparison, especially for fractions with smaller numbers.
Example:
Compare 1/3 and 2/5.
- Draw pie charts for each fraction or use fraction bars.
- You’ll see that 2/5 covers more of the pie or bar compared to 1/3 so 2/5 is larger.
By using these methods, you can effectively compare fractions and determine which one is larger. Practice with different fractions will make these comparisons quicker and easier. You can also use our Free Comparing Fraction Calculator for which fraction is bigger.