NAPLAN

Equivalent Fractions and Simplifying

Equivalent fractions are different fractions that show the same amount, and by Year 5 they become a tool for comparing, ordering and simplifying. In Year 5 (ACARA v9), students use equivalence to compare and order fractions with related denominators — where one denominator is a multiple of another, like halves, quarters and eighths — and to simplify fractions to their smallest form. The key idea: to compare fractions fairly, you rewrite them with the same denominator so the pieces are the same size, then the one with more pieces is larger. Simplifying works the other way — dividing top and bottom by the same number to write a fraction as simply as possible.

Worked examples

Which is bigger: 3/4 or 5/8?

Rewrite 3/4 with denominator 8: 3/4 = 6/8. Now compare 6/8 and 5/8 — same-sized pieces. 6/8 has more.

Answer: 3/4 is bigger

Order from smallest to largest: 1/2, 3/8, 3/4.

Rewrite all as eighths: 1/2 = 4/8, 3/4 = 6/8, and 3/8 stays. Order the eighths: 3/8, 4/8, 6/8.

Answer: 3/8, 1/2, 3/4

Simplify 6/8 to its smallest form.

Divide top and bottom by the same number. Both divide by 2: 6/8 = 3/4. Nothing divides 3 and 4 further.

Answer: 3/4

Real-world: one jug is 2/3 full, another is 5/6 full. Which has more?

Rewrite 2/3 with denominator 6: 2/3 = 4/6. Compare 4/6 and 5/6. 5/6 has more.

Answer: The second jug (5/6) has more

Tips

  • To compare, make the denominators match first. Rewrite the fractions with a common denominator so the pieces are the same size — then just compare the top numbers.
  • Simplify by dividing, not guessing. Find a number that divides both top and bottom (a common factor) and divide by it; repeat until nothing divides both.
  • Common mistake to watch for: children sometimes compare fractions by the top number alone, thinking 3/8 is bigger than 1/2 because 3 is more than 1. The size of the pieces matters — 1/2 is 4/8, which beats 3/8.
  • Use a fraction wall. Lining up halves, quarters and eighths on a wall shows at a glance which fraction is bigger and which fractions are equal.

Key words

Equivalent fractions: different fractions that are the same amount (1/2 = 2/4 = 4/8).Simplify: to write a fraction with the smallest possible numbers by dividing top and bottom (6/8 becomes 3/4).Common denominator: the same bottom number used for two or more fractions so they can be compared.Related denominators: denominators where one is a multiple of another (2, 4 and 8).Common factor: a number that divides evenly into both the top and bottom of a fraction.