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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.
To round a number like 125 to the nearest ten: 25 is equidistant (the same distance) from 20 and 30.
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.
Example: If you want to know what 48 x 12 is then you might round the numbers to 50 x 10.
This makes your estimated answer 500. The real answer should be a similar amount. In fact, 48 x 12 = 576.
To round numbers just ask yourself which ten, hundred or thousand they are nearest to.
Also remember the rule: 5s, 50s and 500s are always rounded UP not DOWN.
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