Because... you just have to divide 4 1/2 by 1/3 so you change 4 1/2 to it’s improper fraction which is 9/2 then you divide it like this- 9/2 / 1/3 = (do the keep change flip method) 9/2 x 3/1 which equals to 27/2
Then you divide 27 by 2 and then it gets you your answer which is 13 1/2