When we compare fractions, we're trying to figure out which fraction is larger, which is smaller, or if they're equal.
There are several strategies we can use to compare fractions, and we'll learn all of them!
This is the easiest type of comparison! When fractions have the same denominator (bottom number), we just compare the numerators (top numbers).
Compare: 3/8 and 5/8
Solution:
• Both fractions have the same denominator (8)
• Compare numerators: 3 < 5
• Therefore: 3/8 < 5/8
When fractions have the same numerator (top number), we look at the denominators. Here's the trick: the smaller the denominator, the LARGER the fraction!
Think about it: Would you rather have 1/2 of a pizza or 1/8 of a pizza? Half is definitely bigger!
Compare: 3/4 and 3/10
Solution:
• Both fractions have the same numerator (3)
• Compare denominators: 4 < 10
• The smaller denominator means larger pieces!
• Therefore: 3/4 > 3/10
Sometimes we can compare fractions by using benchmark fractions - fractions we know well, like 1/2, 1, or 0. This helps us estimate and compare more easily!
Compare: 1/8 and 7/9
Solution:
• 1/8 is close to 0 (the numerator 1 is much smaller than denominator 8)
• 7/9 is close to 1 (the numerator 7 is almost equal to denominator 9)
• Since 7/9 is close to 1 and 1/8 is close to 0: 1/8 < 7/9
Compare: 3/7 and 5/9
Solution:
• Is 3/7 less than or greater than 1/2? Think: Is 3 more or less than half of 7?
→ Half of 7 is 3.5, so 3/7 is slightly less than 1/2
• Is 5/9 less than or greater than 1/2? Think: Is 5 more or less than half of 9?
→ Half of 9 is 4.5, so 5/9 is slightly more than 1/2
• Therefore: 3/7 < 5/9
When fractions have different numerators AND different denominators, we can convert them to have the same denominator. Then we can easily compare them!
To do this, we find a common denominator - usually the Least Common Multiple (LCM) of both denominators.
Compare: 2/3 and 3/4
Solution:
Step 1: Find a common denominator
• Multiples of 3: 3, 6, 9, 12, 15...
• Multiples of 4: 4, 8, 12, 16...
• Common denominator: 12
Step 2: Convert both fractions
• 2/3 = (2×4)/(3×4) = 8/12
• 3/4 = (3×3)/(4×3) = 9/12
Step 3: Compare numerators
• 8/12 < 9/12
• Therefore: 2/3 < 3/4
Compare: 5/6 and 7/8
Solution:
Step 1: Common denominator = 24 (LCM of 6 and 8)
Step 2: Convert
• 5/6 = (5×4)/(6×4) = 20/24
• 7/8 = (7×3)/(8×3) = 21/24
Step 3: Compare: 20/24 < 21/24
• Therefore: 5/6 < 7/8
Great job! You now know four different ways to compare fractions:
Remember: Choose the easiest method for the fractions you're comparing!