Problem of the Week - Upper Elementary - Jan. 31, 2021 to Feb. 6, 2021

Upper Elementary: 

Question: Anna, Brayden, and Caleb have three equally sized pies. Anna ate four fifths of her pie. Brayden ate eight ninths of his pie. Caleb ate nine tenths of his pie. Who has the most pie left over? 

Answer: Anna

Solution: Notice that the numerator in each fraction is one less than the denominator. That means we can solve this problem by thinking of the denomination as the size of the slices; each person ate all but one slice. Since fifths are bigger than ninths and ninths are bigger than tenths, that means that the person with a fifth of a pie—Anna—has the most left over.