Percentages are always out of 100 - imagine the fraction 1/100. If I asked you to work out 1/100 of a number, how would you do it?It's pretty much the same for percentages - because 1% is the same as 1/100. So you can apply the same principle to percentages. If the number is too big, or you don't know that particular times table (most people don't know their 23 times table), you can try and break it down into smaller numbers. For this one, you could work out 20% and 3%. So how would you do that?Divide 650 by 100 (6.5) and then multiply that by 20 (or by 10 and then by 2). Then you can do the same for 3% - divide 650 by 10 again and multiply it by 3. Then add the two together, and that should give you the answer.1. 6.5 x 2 = 13.013.0 x 10 = 130.02. 6.5 x 3 = 19.53. 130.0 + 19.5 = 149.5So Lisa has lost £149.50