Mike paid a total of £4.69 for a chocolate bar, a bag of crisps and a jar of jam. The jar of jam costs £2.19. The chocolate bar costs 57 pence. How much did the bag of crisps cost?
There are two methods of solving this question. First let's look at the prices we already know. The jar of jam is £2.19, or else said 2 pounds and 19 pence. The chocolate bar is 57 pence, so not a whole pound, which is why we write it down as £0.57. We should also remember that there are 100 pence in a pound. And now let's look at the first method:
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Let's first add together the costs for the items we know: the jar of jam and the chocolate bar. £2.19 + £0.57. To make it easier to add let's convert everything to pences, remembering that one pound is 100 pence. Therefore, £2.19 is 2 x 100 + 19 = 219 pence. Now 219 + 57 = 276. Now £4.69 is 4 x 100 + 69 = 469 pence. It is time to substract from 469 the sum of the objects we know the price of. 469 - 276 = 193. 193 is almost 200, but not quite. This means it is still 100 + 93, or otherwise £1.93. Which is the price of the crisps.
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The second method would start just like the first, by converting everything to pence. However, instead of adding the two objects together we just deduct them from the total amount. 469 - 219 - 57 = 193. Again, following the method above, we convert it to £1.93
