Units and Dimensions - Arithmetics With Significant Figures

Description:

The result contains as many significant figures as there are in the number with least number of significant figures.

Example

3.02 contains 3 (three) significant digits

200.12 contains 5 (five) significant digits

Multiplying − 3.02 × 200.12

Pure arithmetic result: 3.02 × 200.12 = 604.3624

However, by the rule, Result = 604 (3 significant digits)

Dividing − 200.12/3.02

Pure arithmetic result: 200.12/3.02 = 66.2649006623

However, by the rule, Result = 66.2 (3 significant digits)

The result contains as many decimal places as there are in the number with least decimal places.

Example −

3. 2 contains 1 (one) digit after decimal.

200.12 contains 2 (two) digits after decimal.

Adding − 3.2 + 200.12

Pure arithmetic result: 3.2 + 200.12 = 203.32

However, by the rule, Result = 203.3 (1 decimal place)

Substracting − 200.12 - 3.2

Pure arithmetic result: 200.12 − 3.2 = 196.92

However, by the rule, Result = 196.9 (1 decimal place)

If the insignificant digit is more than ‘5’ (five), the preceding digit is raised by ‘1’ and the insignificant digit is dropped.

If the insignificant digit is less than ‘5’ (five), the preceding digit is kept as it is and the insignificant digit is dropped.

If the insignificant digit is equal to ‘5’ (five), then,

If the preceding digit is odd, it is incremented by 1. The insignificant digit is dropped.
- E.g.: 3.0254 rounded to 3 significant digits: 3.02,

If the preceding digit is even, it is left as it is. The insignificant digit is dropped.
- But, 3.0154 rounded to 3 significant digits: 3.02

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