Adding fractions with the same denominator worksheets

Each problem adds two fractions with the same denominator, such as 3/8 + 2/8. Students add the numerators, keep the denominator, and then simplify. The answer key gives the simplified answer worked out with whole numbers only. When a sum is greater than 1, it shows both forms, for example 9/8 = 1 1/8, so you can accept whichever form your class uses.

When to use it

Use this sheet when students understand what a fraction is and can recognise equivalent fractions. It is a natural first step in adding fractions, and it builds the reasoning students need later for unlike denominators. A largest denominator of 8 keeps numbers manageable. Raise it to 12 for more challenge.

Teaching tips

• Use the language of units: “3 eighths plus 2 eighths is 5 eighths,” just like 3 apples plus 2 apples.
• Address the most common mistake head-on: adding the denominators too (3/8 + 2/8 = 5/16). A fraction strip shows quickly why that is wrong.
• Have students simplify as a separate final step and circle it, so they don't forget.
• For sums bigger than 1, connect improper fractions to mixed numbers with a number line.
• Ask students to estimate first: is the sum more or less than one whole?

How to print this worksheet

1. Check the settings above. They are already set for adding fractions with the same denominator.
2. Pick 10, 15, 20 or 30 problems, a title, and the name or date lines you want.
3. Choose US Letter or A4 to match the paper in your printer.
4. Press Download PDF for a file you can save and reuse, or Print to send it straight to your printer.
5. Keep the answer key page for yourself. The sheet number in the footer lets you make the exact same sheet again later.

What comes next

Next, practise subtracting fractions with the same denominator (choose “Subtract” in the fraction type setting). Then move on to adding fractions with different denominators in your main curriculum, which uses the equivalent fractions skill to rewrite both fractions first.