When you round a number, you write it as an approximation of the original number: numbers can be rounded upwards and downwards. For example, 127 rounded to the nearest ten is 130 because 27 is closer to 30 than to 20. If you round 127 to the nearest hundred, it becomes 100 because 127 is nearer to 100 than to 200. All is well until someone asks you to round a number like 125 to the nearest ten: 25 is equidistant (the same distance) from 20 and 30. What do you do in such cases? You follow this RULE:
If the number that you use to decide whether to round upwards or downwards (let's call it the deciding number) is halfway or closer to the number to which you have to round to, round upwards BUT if it is less than halfway to the number to which you have to round to, round downwards.
Try these 11-plus Maths questions and see how easy rounding really is.