Three stage problems

Three stage problems need three separate calculations to find the answer.

Your friend has £5. She buys a magazine costing £1. Inside the magazine is a coupon which offers 50p off some sun cream. In the shop the sun cream is priced at £3.50. Your friend buys the sun cream getting 50p off the price by using the coupon.
How much money should your friend have left from her £5?

"Mmm... I'm confused by the question. I'll read it through a bit at a time to see if it makes sense. Actually it is OK. I think I can do it in my head - she bought the magazine first and took out the coupon. Then in the shop she found the sun cream priced at £3.50. At the checkout she used the coupon to get 50p off the price of the sun cream. She went out with £5, so I can work out how much she should have left. So I will use addition and subtraction".

Magazine: £1.00 spent
Sun cream: £3.50 - 50p (using coupon for 50p off the price)
So, £1 spent on a magazine and £3 spent on sun cream = £4 spent in total
£5 - £4 = £1

Your friend should have £1 change from her £5