Age 7 to 11 Challenge Level:
Mollie of St.Michael's C.of.E Primary
School, Sandhurst, laid out her method very carefully:
Firstly I needed to work out all the actual prices for all the
items at Gary's Groceries:
Chocobiscuits= 94p- 50%= 47p
Oven Chips= £1.60 - 25%= £1.20
Crisps= £1.20 - 35% = 70p
Lemonade= 55p - 20% = 44p
Sausages= £1.85 - 40% = £1.11
Secondly Ihad to work out how much was saved on each
Oven Chips= 40p
Mrs Lydford's groups of Balgowan Primary
School then found the cost of the shopping list at each
Gary's Groceries= 2 x 44p + 1 x 78p + 3 x 111p + 1 x 120p = 619p =
Fiona's Food's= 2 x 43p + 1 x 99p + 3 x 104p + 1 x 155p = 650p =
Paul's Provision's= 1 x 90p (using buy one get one free) + 1 x 159
+ 2 x 204 (two bought at buy one get one free, the third bought at
full price) + 1 x 249p = 906p = £9.06
Gary's Groceries would be the cheapest place to buy the whole
shopping list, at £6.19, compared with £6.52
at Fiona's Foods and £9.06 at Peter's Provisions, but it
would be even cheaper to shop around, buying lemonade and sausages
at Fiona's Foods, crisps and chips at Gary's Groceries for a total
We thought the disadvantages of doing it this way would be that we
would use more time and petrol.
Mollie added the following disadvantages to
shopping at just one place:
- it might take different times to get to each of the shops.
- the shop might not have the type you want.
- the shop might be surrounded by more houses so be more popular
and therefore have less stock.
Then Mrs Lydford's groups found some
different ways not to go over their allotted £10.70
budget for the party food, by first working out which was the
cheapest place to buy each item:
For the party, we found 8 ways of buying the food for under
£10.70 by shopping around.
First we bought all the items in the cheapest places:
lemonade=£1.72 at Fiona's
sausages=£4.08 at peter's
chips=£2.40 at Gary's
crisps=£1.56 at Peter's
biscuits=84p at Fiona's
Next we substituted items which were close in price to make
different totals, still under £10.70.
Change lemonade to Gary's - new total £10.64
Change lemonade to Peter's - new total £10.68
Change chips to Peter's - new total -£10.69
Change crisps to Peter's - new total - £10.63
Change biscuits to Peter's - new total - £10.65
Change biscuits to Gary's - new total - £10.70
Change lemonade to Gary's and crisps to Peter's - new total -
Finally, Mollie answered the last part of
Buy one get one free is the same as 50 % off as you are getting
double for the money in both situations. Hoever 50% off
Ithink is better because you can decide whether to buy
two lots where as with buy one get one free you might not use them
within the sell by date.
If none of the supermarkets had a special promotion, I would shop
at Fiona's, because she sells smaller packages but she charges less
for them, so you can use them by the sell by date.