Significant Figures & Rounding

Correctly represent uncertainty in measured quantities using significant figures

Rule 1: Non-zero digits: In numbers that do not contain zeros, all the digits are significant.

Rule 2 Captured zero: All zeros between significant digits are significant.

Rule 3 Preceding zero: Zeros to the left of the first nonzero digit serve only to fix the position of the decimal point and are not significant.

Rule 4 ending zero: In a number with digits to the right of a decimal point, zeros to the right of the last nonzero digit are significant.

Apply rules for significant figures to express uncertainty in measured and calculated values.

Significant figures

Significant figures are the number of digits in a value, often a measurement, that contribute to the degree of accuracy of the value.

Tutorial (Tyler DeWitt) Significant Figures

Significant figure playlist

Apply proper rounding rules to computed quantities (1.5)

The least certain value in terms of addition and subtraction

When adding or subtracting numbers, round the result to the same number of decimal places as the number with the least number of decimal places.

Round to least # of decimal places

The least certain value in terms of multiplication and division

When multiplying or dividing numbers, round the result to the same number of digits as the number with the least number of significant figures.

Round to the smallest # of sig figs

Round to even rule for 5's

When the value you intend to round off is a five, you MUST look at the previous value ALSO. If it is even, you round down. If it is odd, you round up. A common question is "Is zero considered odd or even?" The answer is even.

Round to even rule for 5's

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