Acompact disc player costs £50 plus 17 1/2% vat. calculate the total cost of the compact disc player

With Calculator:
To work out the multiplier, take the percentage, divide by 100 and add 1
17.5% / 100 = 0.175
1 + 0.175 = 1.175
£50 x 1.175 = £58.75

Without Calculator:
First work out easy percentages of 50 (if needed use previous answers (such as 10) to work out smaller percentages (such as 5%))
100% = 50
10% = 5
5% = 2.5
2.5% = 1.25
10% + 5% + 2.5% = 17.5%
5 + 2.5 + 1.25 = £8.75
Add this on to the original price:
£50 + £8.75 = £58.75

The total price, including VAT, is £58.75