80% of UK Population Lack Mental Arithmetic Skills

From the ES:

Almost 80% of Britons are incapable of roughly dividing £9bn by 71m, according to a new poll that shows that most people can't do rough mental arithmetic that shows a troubling state of mathematics.

A Guardian/ICM poll showed that 78% of voters believed the Olympics "were probably costing me about the same as a box of Milk Tray", as compared with just 20% who had done the sums and knew that they were actually spending at least half their family's mortgage to get exactly what they would have got if Paris had hosted them.