How do I know how many sig figs to use?

[Ava_Basileo_2J]

If there are multiple values in a prompt, each with a different number of sig figs, how many sig figs should my final answer have?

[Hayden Lee 1C]

Hi there!

The amount of sig figs used is dependent on how you completed the problem. With multiplication and division, the lowest number of sig figs used will be the number of sig figs included in your answer. With addition and subtraction, you assign significant figures based on the number of decimal places in the numbers used (use the smallest number of decimal places). These rules do not include intermediate steps. Hope this helps!

[Heidi Buri 2I]

Hi! There are different rules for addition/subtraction or multiplication/division. When values are being added/subtracted, the final answer should have as many decimal places as the given value with the least amount of decimal places. For multiplication/division, the answer should have the same amount of significant figures as the value given with the least amount of significant figures.

[kristinalaudis3e]

When you multiply or divide, your answer should have the same number of sig figs as the value with the smallest number of significant figures. 55.5 (3 sig figs) / 2.5 (2 sig figs) = 22.2, but you need only 2 sig figs so it would be 22. When you add or subtract, you answer should have the same number of sig figs as the least precise number (which can be determined by the least number of decimal places). 2.0009 (5 sig figs) + 1.001 (4 sig figs) = 3.0019 but you only need 4 decimal places, so you can round to 3.002. I hope this helps!

[Hannah Alltucker 3L]

If the problem involved only addition and subtraction, use the value of sig figs for the least accurate number (so base the answers sig figs on the number that has the least sig figs present in the problem)

If the problem involved multiplication or division, then use the least amount of sig figs that came after the decimal point (so base answers on the least amount of sig figs after the decimal point of the values present in the problem)

[Sheryl Ocampo 1D]

For addition and subtraction, your answer should have the same number of decimal places as the lowest number. For multiplication and division, your answer should have the same number of significant digits as the number with the fewest sig figs

[Rachel Jiang 3H]

Hi! The number of sig figs of your answer is dependent on the way you calculate. For addition and subtraction, round to the last sig fig of the least precise number. For multiplication and division, your final answer should have the same number of sig figs as the least precise value given in the original problem. Hope this help!