Sam's grandmother has an old recipe for cherry buns. She has enough
mixture to put 45 grams in each of 12 paper cake cases. What was
the weight of one egg?
Mum, Dad, Tim and Jill moved into a new house. If they cut down the
big tree, will it miss the greenhouse?
A 750 ml bottle of concentrated orange squash is enough to make
fifteen 250 ml glasses of diluted orange drink. How much water is
needed to make 10 litres of this drink?
It looks like Peter is going to have to go shopping!
A way to think about this problem was to find out what
proportion of the original recipe Peter required to make the two
pies. You might have divided and then perhaps multiplied, depending
on your strategy. Using what you know about fractions could have
helped. A number of you sent the answer that Peter was short of
some of the ingredients. There were two ways that the problem was
solved and fully explained. These mathematicians came up with the
following solutions and used their knowledge of decimals.
Ruth who lives in
Gloustershire, decided that the answer to the Pumpkin Pie
Problem is, he hasn't got enough ingredients to make two pies.
She got the answer by dividing the ingredients by 80 and
multipliyingby 2. Both Helena from Tattingstone
School, and George of Rosebank Primary
School, Leeds, divided mother's recipe by 40. Why do you think they
decided to do this?
solution, she did an excellent job of setting out her calculations
in a chart.
George both provided
clear explanations. George explained: "To find out if Peter had
enough to make 2 pies I divided each of the ingredients by 40. For
the 10 dozen eggs I first multiplied 10 by 12, because dozen means
12. Then I divided the answer by 40.
10 X12 = 120.
120 / 40 = 12 / 4 = 3
Peter had 2 eggs but he needed 3 eggs so he had to buy 1 more
To find out how many litres of condensed milk was needed, I
first converted the litres of condensed milk into millilitres of
condensed milk. Then I divided the answer by 40 again.
27litres X 1000 = 27,000ml
27,000ml / 40 = 675ml
Peter had 666ml but he needed 675ml so he needed to buy 9ml of
To find out how many tablespoons of sugar Peter needed I just
divided the amount for 80 pies by 40.
480 / 40 = 12 tablespoons of sugar.
Peter had 15 tablespoons of sugar so he had 3 more.
To find out how many teaspoons of cinnamon, I divided the
original amount again by 40.
100 / 40 = 10 / 4 = 2.5 teaspoons of cinnamon.
Peter had 1.5 teaspoons of cinnamon, so he needed to buy 1 more
teaspoon of cinnamon.
Finally, to find out how many cups of pumpkin were needed I
divided 140 by 40.
140 / 40 = 14 / 4 = 3.5 cups of pumpkin.
Peter had 4 cups of pumpkin so he had 0.5 cups of pumpkin more
than he needs".