Scales, Standards, Units and Significant Figures

A set of vocabulary flashcards covering the definition, rounding rules, and arithmetic application of significant figures.

Significant Figures

The digits in a number where each non-zero digit is counted, and zeroes are included only if they are placed between two non-zero digits or are at the end of the decimal part.

Significant figures in the number $2000$

There is only $1$ significant figure, which is the digit $2$.

Significant figures in the number $2000.0$

There are $5$ significant figures.

Rounding Significant Figures

The process of removing digits from the right of a number until the desired count is reached, rounding the final value as you go.

$6.827$ to $3$ significant figures

$6.83$, achieved by removing the $7$ and rounding the previous digit up.

Significant Figure Rule for Addition and Subtraction

The final result must have the same number of decimal places as the term in the calculation with the smallest number of decimal places.

Calculated Sum of $9.65$ and $8.4$

$18.1$, because the measured value $8.4$ has only one decimal place, which is the fewest in the set.