Rules for determining significant figures -
When the value of the measurement is to be rounded off to given number of significant figures,then the figure to be dropped is (1) less than 5,then the last insignificant figure is left unchanged (2) 5 or greater than 5,the last significant figure is increased by one.
When the value of the measurement is to be rounded off to given number of significant figures,then the figure to be dropped is (1) less than 5,then the last insignificant figure is left unchanged (2) 5 or greater than 5,the last significant figure is increased by one.
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example 1
> let's round 37.6214 to four significant digits
> the four significant digits are 37.62
> 2 is the last significant figure
> the number to the right of the last significant figure is less than 5 so the last significant figure is not changed
> final output 37.62
example 2
> let's round 2.874 to two significant digits
> the two significant digits are 2.8
> 8 is the last significant figure
> the number to the right of the last significant figure is greater or equal to 5 so the last significant figure is bumped up by one.
>final output is 2.9
> let's round 37.6214 to four significant digits
> the four significant digits are 37.62
> 2 is the last significant figure
> the number to the right of the last significant figure is less than 5 so the last significant figure is not changed
> final output 37.62
example 2
> let's round 2.874 to two significant digits
> the two significant digits are 2.8
> 8 is the last significant figure
> the number to the right of the last significant figure is greater or equal to 5 so the last significant figure is bumped up by one.
>final output is 2.9
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It is very straight forward
While rounding off if the next digit is 'less than half part ' ignore and if 'half and more' take as whole
Let me give an example suppose 1.234 is to be rounded off to two places of decimal the we tale it as 1.23 ignoring the next digit which is4 and it is 'less than 5'
On the other hand if the number were 1.235 or 1.236 etc we would have rounded these to 1.24 because the next digit in these two examples were '5 or more ' Ok?
While rounding off if the next digit is 'less than half part ' ignore and if 'half and more' take as whole
Let me give an example suppose 1.234 is to be rounded off to two places of decimal the we tale it as 1.23 ignoring the next digit which is4 and it is 'less than 5'
On the other hand if the number were 1.235 or 1.236 etc we would have rounded these to 1.24 because the next digit in these two examples were '5 or more ' Ok?