HOW DO YOU ADD UP?

National Numeracy offers a free online test to assess your skills. The answers are below.

Books cost £5 each. Which is the best deal: buy one get one half price, or two for the price of one?

Three bottles of detergent cost 750ml for £2.40, 500ml for £1.60 and 1,000ml for £3.20. Which is the best value?

Rail tickets increased in price by 2pc in year one, and 3pc in year two. What was the overall increase over the two years?

Gas costs 4p per kwh, with a standing charge of 22p per day. If you use 12,350 kwh of gas a year, what is a sensible amount for a monthly direct debit?

How long would one million seconds be in days?