Practice Adding Fractions with Unlike Denominators in Math
Use these practice problems to test your method after reviewing the concept explanation and worked examples.
Quick Recap
Adding fractions with different denominators by first rewriting them with a common denominator (usually the LCD), then adding numerators.
You can't add thirds and fourths directly—it's like adding apples and oranges. Convert both to twelfths first, then add.
Showing a random 20 of 50 problems.
Example 1
easyAdd . 3/5 + 1/10 = 7/10
Example 2
mediumSubtract . 7/10 − 2/5: how much more is shaded in the top bar?
Example 3
mediumFill in the blank: .
Example 4
hardExpress in lowest terms.
Example 5
mediumA board is m long. Another is m. Total length end-to-end?
Example 6
mediumAdd .
Example 7
hardSolve for : .
Example 8
mediumSubtract . 5/6 − 1/4: compare the two shaded amounts
Example 9
easyAdd . 1/3 + 1/12 = 5/12
Example 10
challengeTelescoping: compute .
Example 11
easyAdd . 1/3 + 1/6 = 1/2
Example 12
easyAdd . 1/2 + 1/3 = 5/6
Example 13
challengeFind in lowest terms.
Example 14
mediumSubtract .
Example 15
mediumA jug holds liter; you add liter more. How much is in the jug? Jug: 2/3 L + 1/4 L = 11/12 L
Example 16
hardWorked example: a chef uses kg of butter on Monday, kg Tuesday, and kg Wednesday. Total used?
Example 17
hardCompute .
Example 18
easyAdd . 2/5 + 1/10 = 1/2
Example 19
mediumWorked example: add .
Example 20
mediumWorked example: add and explain the LCD choice.