Math

Assuming a Bigger Denominator Means a Bigger Fraction

Students think 18\frac{1}{8} is bigger than 14\frac{1}{4} because 88 is bigger than 44.

Quick check

Why students make it

Students use whole-number thinking on the denominator. They forget that the denominator tells how many equal pieces the whole is split into, so a bigger denominator means smaller pieces when the numerator stays the same.

The rule done right

For fractions with the same numerator, the fraction with the smaller denominator is bigger. For example, 14>18\frac{1}{4} > \frac{1}{8} because fourths are larger pieces than eighths.

Related resources

fractionsdenominatorscomparing-fractions