- #1

vcsharp2003

- 749

- 162

- Homework Statement:
- If ##r## and ##d## are radius and diameter of a given circle, then to determine radius from diameter we use the formula ##r = d \div 2##. Suppose, ##d=5## then ##r=5 \div 2 = 2.5##. I have a question regarding significant digits in this calculation. We know the significant digits rule for dividing two numbers is that the resulting value must have as many significant digits as the minimum number of significant digits of dividend and divisor. In this case the minimum number of significant digits is 1 for dividend or the divisor, and therefore why we don't apply this rule and express the answer as a number up to 1 significant digit?

- Relevant Equations:
- ##r = d \div 2##

Probably, to satisfy the significant digits rule for division, we should consider ##r = 5.0 \div 2.0##. But I'm unable to come up with a reason why significant digits rule should not apply to ##r= d \div 2##. Also, if we apply significant digits rule to this calculation then we loose accuracy and so we should ignore the significant digits rule.

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