Rounding

Rounding to significant figures 

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Rounding to significant figures has many uses for example if a journey is 6924 miles long then it would be much easier to round it up to the nearest thousand, 7000 miles. 

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To round to a significant figure you 

• If rounding to the first significant figure you look at the first digit that is NOT 0.

• Look at the digit after the one you are rounding to. eg if rounding 6924 to 1 SF, look at the 9.

• If the digit is 5 or more then you round up. eg 583 to 1 SF would round to 600.

• If the digit is 4 or less then you round down. eg 543 would round to 500.

• fill in any spaces to the right of the rounded number with 0's.

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Example

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543,576 to 2 significant figures

1. 54|3576

2. 3 is 4 or less so we round down

3. 54 and fill in all spaces to the right with 0's 

4. So the answer is 540,000

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