1.) 10/12 - 1/4 5.) 5.)4/5 -1/3 9.) 9.) 9/9 -2/3. 13.) 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 need to fill? 15.)gracie read 150 pages of a book. the book is 227 pages long. which equation shows the amount she still needs to read to finish the story? 16.) why do fractions need to have a common denominator before you add or subtract them?