Question

Zoe Had A Board 5 And 1/4 Feet Long. She Cut Off A Piece. Now The Board Is 3 And 5/6 Feet Long. How Long Was The Piece She Cut Off?

Answer 1

Well first you need to find the LCM (least common multiple) of 4 and 6 (the denominators) so that you can subtract them from each other.

4: 4,8,12,16,20
6: 6, 12, 18, 24
The LCM is 12.

Now we can subtract the two mixed numbers by turning them into improper fractions.

5 3/12 -> 27/12
3 10/12 -> 42/12

42-27=15

The fraction is 15/12, which simplifies into 1 1/4.

She cut off 1 1/4 feet of the board.