Significant figures

nightguy · Mar 4th, 2002, 08:39 AM

How do I round a number to, say, 3 significant figures?

e.g.

123456 goes to 123000
123654 goes to 124000

1234 goes to 1230
1245 goes to 1250 (round upwards)

123 goes to 123 (unchanged)
1.234 goes to 1.23
0.0001234 goes to 0.000123

I think you can do it by taking logs and using the ROUND function, but is there a more direct method?

Thanks!

Steve Hartman · Mar 4th, 2002, 08:50 AM

=ROUND(A1,A2-1-INT(LOG10(A1)))

where A1 is the number to round and A2 is the number of signficant digits to round to.

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Mar 4th, 2002, 08:39 AM	#1
nightguy New Member Join Date: Feb 2002 Posts: 11	How do I round a number to, say, 3 significant figures? e.g. 123456 goes to 123000 123654 goes to 124000 1234 goes to 1230 1245 goes to 1250 (round upwards) 123 goes to 123 (unchanged) 1.234 goes to 1.23 0.0001234 goes to 0.000123 I think you can do it by taking logs and using the ROUND function, but is there a more direct method? Thanks!

Mar 4th, 2002, 08:50 AM	#2
Steve Hartman Board Regular Join Date: Feb 2002 Location: Houston,Texas Posts: 418	=ROUND(A1,A2-1-INT(LOG10(A1))) where A1 is the number to round and A2 is the number of signficant digits to round to.