###### Asked in Science

Science

# Rules in determining significant figures in four fundamental operations?

## Answer

###### Wiki User

###### July 15, 2009 8:12AM

The simple rule is: no more significant figures than the least accurate of the values in the computation. For multiplication and division, the result should have as many significant figures as the measured number with the smallest number of significant figures. For addition and subtraction, the result should have as many decimal places as the measured number with the smallest number of decimal places. (Rounding off can be tricky, but that would be another thread)

## Related Questions

###### Asked in Math and Arithmetic

### What is the greatest number that rounds to 700?

That depends on how many significant figures you are talking
about.
If three significant figures then 700 is the largest that rounds to
700.
If four significant figures are to be rounded to three significant
figures then 700.4
If five significant figures are to be rounded to three significant
figures then 700.49
If six significant figures are to be rounded to three significant
figures then 700.499
etc.

###### Asked in Science, Math and Arithmetic

### What are the rules in the determining the number of significant figures?

The rules for identifying significant figures when writing or
interpreting numbers are as follows:
All non-zero digits are considered significant. For example, 91
has two significant figures (9 and 1), while 123.45 has five
significant figures (1, 2, 3, 4 and 5).
Zeros appearing anywhere between two non-zero digits are
significant. Example: 101.1203 has seven significant figures: 1, 0,
1, 1, 2, 0 and 3.
Leading zeros are not significant. For example, 0.00052 has two
significant figures: 5 and 2.
Trailing zeros in a number containing a decimal point are
significant. For example, 12.2300 has six significant figures: 1,
2, 2, 3, 0 and 0. The number 0.000122300 still has only six
significant figures (the zeros before the 1 are not significant).
In addition, 120.00 has five significant figures since it has three
trailing zeros.