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# Rounding numbers

A rounded number has about the same value as the number you started with but is less exact.

## Rules for rounding

• Identify the place value you are rounding to. For example, for rounding currency to the nearest cent use 2 decimal places (hundredths).
• Look at the digit to the right of this place:
• If this number is less than 5 (0, 1, 2, 3, 4) you leave your last digit as it is.
• If it is 5 or more (5, 6, 7, 8, 9) you increase the value of your last digit by one.
• Any digits after your place become zeros or are dropped off if they are to the right of the decimal point.

## Examples:

 1. Round to the nearest cent: Rounded (a)  \$72.3483844 \$72.35 (b)  \$104.2309 \$104.23 (c)  \$2.3981007 \$2.40 2.    Round to the nearest 100: (a)  1,237 1,200 (b)  127,899 127,900 (c)  945,555,972 945,556,000

## Rounding to the nearest whole number

The usual rules for rounding apply in most situations when rounding to a whole number. However, in some situations, the correct answer will always require rounding up.

For example:
Bottled water is sold in packs of 12. How many packs need to be ordered to ensure that all 147 staff get a bottle of water?

Calculation 147 ÷ 12 = 12.25
Conventional rounding would mean this number would be rounded down to 12.

But notice that 12 x 12 = 144 so 3 staff would miss out.
The correct answer is that 13 packs should be ordered to ensure every staff member gets a bottle of water.