the pet shop owner told Jean to fill her new fish tank 3/4 full with water. Jean filled it 9/12 full . what fraction of the tank does Jean still need to fill?

Answer 1

Chance 3/4 to an equivalent fraction with 12 in the denominator. Do this by multiplying both the 3 and the 4 by 3.
Compare this with 9/12

Answer 2

8/245 just because.