Practice Adding Fractions with Like Denominators in Math

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

Quick Recap

Adding fractions that share the same denominator by adding the numerators and keeping the denominator.

If you have 25\frac{2}{5} of a pie and get 15\frac{1}{5} more, you now have 35\frac{3}{5}β€”same size pieces, just count them up.

Showing a random 20 of 50 problems.

Example 1

medium
311+?11=1011\frac{3}{11}+\frac{?}{11}=\frac{10}{11}. Find the missing numerator.

Example 2

challenge
For positive integer nn, simplify 1n+2n+3n+β‹―+nn\frac{1}{n}+\frac{2}{n}+\frac{3}{n}+\cdots+\frac{n}{n} in closed form.

Example 3

easy
A bowl has 410\frac{4}{10} kg of rice. You add 310\frac{3}{10} kg more. How much rice is in the bowl?

Example 4

medium
Add 29+49+19\frac{2}{9}+\frac{4}{9}+\frac{1}{9}.

Example 5

medium
Express 420+620\frac{4}{20}+\frac{6}{20} in lowest terms.

Example 6

easy
Add 16+46\frac{1}{6}+\frac{4}{6}.

Example 7

challenge
Express 18+18+18+18\frac{1}{8}+\frac{1}{8}+\frac{1}{8}+\frac{1}{8} as a single fraction and as a decimal.

Example 8

medium
Find the missing numerator: 413+β–‘13=1113\frac{4}{13}+\frac{\square}{13}=\frac{11}{13}.

Example 9

medium
Add 58+78\frac{5}{8}+\frac{7}{8} and write the result as a mixed number.

Example 10

medium
Two ribbons are 38\frac{3}{8} m and 48\frac{4}{8} m. What is their total length?

Example 11

medium
Add 238+1782\frac{3}{8}+1\frac{7}{8}.

Example 12

hard
Bag A has 512\frac{5}{12} kg of flour, bag B has 712\frac{7}{12} kg, bag C has 1112\frac{11}{12} kg. Total mass?

Example 13

easy
Worked example: add 26+36\frac{2}{6}+\frac{3}{6} and show why the denominator does not change.

Example 14

medium
Compute 1120+1320\frac{11}{20}+\frac{13}{20} and write as a mixed number.

Example 15

medium
Add 415+615\frac{4}{15}+\frac{6}{15} and simplify.

Example 16

hard
Find all positive integers n≀10n\le 10 such that n12+n12\frac{n}{12}+\frac{n}{12} simplifies to a unit fraction 1k\frac{1}{k}.

Example 17

easy
True or false: 310+210=520\frac{3}{10}+\frac{2}{10}=\frac{5}{20}.

Example 18

easy
Add 14+14\frac{1}{4}+\frac{1}{4}.

Example 19

challenge
If a12+b12=912\frac{a}{12}+\frac{b}{12}=\frac{9}{12} and a=2ba=2b, find aa and bb.

Example 20

easy
A jug contains 27\frac{2}{7} litre of water. You pour in another 37\frac{3}{7} litre. How much water is in the jug?