To compare fractions with different bottoms, rename them so the bottoms match. Then the one with more pieces is bigger.
Worked example
Which sign goes in the middle?
Answer:35 > 14
Rename both so the bottoms match — twentieths: 35 = 1220 and 14 = 520. Now compare the tops: 12 and 5. So 35 > 14.
35=1220
14=520
For grown-ups: Compare any two fractions (common denominator, common numerator, or benchmark ½). Below: three problems to try with the worked answers, and a free printable sheet. Children can practise the same skill as a game, with no sign-up and no ads.
CCSS 4.NF.A.2
What this practises, for teachers
Practices compare any two fractions (common denominator, common numerator, or benchmark ½) (4.NF.A.2). A printable sheet with its answer key, worked answers on the page, no accounts.