Mathematics · Grades 4–7
Fraction reasoning and common mistakes · Revision card
Comparisons require the same whole. Equal-sized parts give the denominator meaning.
Understand the idea
Think about the whole
Comparisons require the same whole. Equal-sized parts give the denominator meaning.
Choose a check
Use a number line, an equivalent fraction or a benchmark such as one half.
Check the operation
Addition does not add denominators; multiplying by a fraction below one can make a positive value smaller.
Worked examples
Which fraction is closest to one half: 1/8, 4/9, 7/8 or 1/10?
4/9 differs from 1/2 by only 1/18.
4/9
A learner writes 2/5 + 1/5 = 3/10. What is the correct sum?
The equal fifths stay fifths: (2 + 1)/5 = 3/5.
3/5
Explain without looking
- A learner says that a larger denominator always means a larger fraction. Give a counterexample.
Further reading and review references
These are reference links, not copied exercises, institutional endorsement or proof of independent review.
Preview material · independent educational review required. Grade bands are approximate, not official curriculum alignment.