The idea in brief. Compare fractions of equal wholes by rewriting them as equal-sized parts. Compare fractions of equal wholes, and remember a larger denominator means smaller parts. In the lesson. You know that one half and two quarters are equivalent fractions. We multiply the numerator and the denominator by 2. Today, we will compare and order unlike fractions, which have different denominators. To compare fractions, first make the parts the same size. Then compare the numerators.
Lesson video, with the working
Compare fractions
4 min 46 s
The film teaches 3 questions in turn. Each question shows first; its working is written as the film explains it.
How do you tackle comparing and ordering fractions questions in P3?
Here your child learns to compare and order fractions whose denominators are different.
What your child learns here
Here your child learns to compare and order fractions whose denominators are different. It covers the P3 outcome on comparing and ordering unlike fractions with denominators not exceeding 12, using equivalent fractions to make the parts the same size.
Explain why two fractions with different denominators cannot be compared by their numerators straight away.
Rename one or more fractions so they share a denominator, using a common multiple up to 12.
Compare the numerators once the parts match, and say which fraction is greater or smaller.
Arrange three fractions from smallest to greatest, or from greatest to smallest, as the question asks.
Apply the comparison to word problems about who has more of equal wholes.
Does the answer make sense?
When two fractions have the same numerator, the one with the larger denominator is smaller, because its parts are smaller. In your child's list from smallest to greatest, any fraction less than one half, with a numerator under half its denominator, must come before any fraction greater than one half.
How to practise these questions
The Basic questions practise comparing fractions with the same numerator or the same denominator. The Intermediate questions add unlike fractions, which your child turns into equivalent fractions with a common denominator first. The Challenge questions ask for four fractions to be ordered, or for the unpainted parts of two boards to be compared, so a common denominator must suit them all. If comparing fractions stalls, watch the solution film for it and try once more later from Revision. Its multiple-choice Basic questions ask for the smallest or the greatest of four fractions; the written working sets out each comparison, and there is no film for them.
Questions parents ask
What does 'unlike fractions' mean in P3? Unlike fractions have different denominators, such as 2/3 and 5/6. The Primary 3 syllabus asks children to compare and order unlike fractions whose denominators are not more than 12. They are compared by renaming them so the parts are the same size.
Can my child compare fractions by drawing them? Yes, as long as both drawings use wholes of the same size. Two equal bars cut into different numbers of parts show the comparison clearly. Renaming on paper is quicker once your child understands why it works.
Why is 1/8 smaller than 1/4 when 8 is bigger than 4? The denominator tells how many equal parts the whole is cut into. Cutting the same whole into 8 parts makes each part smaller than cutting it into 4. Folding one sheet of paper into quarters and another into eighths shows this in a minute.
