Maths Library

Simplifying Fractions: Grade 4 math

Students practise reducing fractions to their simplest form by dividing numerator and denominator by common factors. The sheet develops efficiency in identifying highest common factors to write fully simplified fractions.

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What this covers

Simplifying Fractions is taught in Grade 4 (age 9 to 10) as a main teaching focus. It sits in the Fractions strand.

Worked example

Simplify 1824 to its simplest form.

  1. Identify the highest common factor of 18 and 24, which is 6.
  2. Divide the numerator by 6: 186 = 3.
  3. Divide the denominator by 6: 246 = 4.

Answer: 34

Difficulty scale

The sheet generator offers five difficulty settings for this topic.

  1. Small numbers with obvious common factors 2, 5, or 10
  2. Numerators and denominators up to 36 with common factors from 2 to 6
  3. Larger fractions requiring division by factors up to 12 in one or two steps
  4. Fractions with numerators up to 100 requiring identification of the highest common factor
  5. Improper fractions simplified fully to simplest improper or mixed form

Common mistakes

  • Stopping before reaching the simplest form after dividing by a non-highest common factor
  • Dividing the numerator and denominator by different numbers

Curriculum links

Indicative matches to Common Core State Standards. Check wording and codes against the official document.

  • 4.NF.A.1 Explain and generate equivalent fractions by multiplying or dividing the numerator and denominator by the same number.

Sample sheet and answers

Six questions at the level's usual difficulty. Open the editor to change, add or regenerate any of them.

Simplifying Fractions

Grade 4 math

Qs
6
Marks
6
NameDateScore / 6
1.
Simplify 525.
[1]
2.
Simplify 816.
[1]
3.
Simplify 36.
[1]
4.
Simplify 36.
[1]
5.
Simplify 46.
[1]
6.
Simplify 36.
[1]

Answer key

  1. 15Divide the top and bottom by the highest common factor, 5; 5 ÷ 5 = 1, 25 ÷ 5 = 5
  2. 12Divide the top and bottom by the highest common factor, 8; 8 ÷ 8 = 1, 16 ÷ 8 = 2
  3. 12Divide the top and bottom by the highest common factor, 3; 3 ÷ 3 = 1, 6 ÷ 3 = 2
  4. 12Divide the top and bottom by the highest common factor, 3; 3 ÷ 3 = 1, 6 ÷ 3 = 2
  5. 23Divide the top and bottom by the highest common factor, 2; 4 ÷ 2 = 2, 6 ÷ 2 = 3
  6. 12Divide the top and bottom by the highest common factor, 3; 3 ÷ 3 = 1, 6 ÷ 3 = 2