Rules for Rounding
The answer to numbers that are multiplied or divided may only have as many significant figure as the number being multiplied or divided with the least amount of significant figures. This is the only level of accuracy that you can be sure of.
The answer to numbers that are multiplied or divided may only have as many significant figure as the number being multiplied or divided with the least amount of significant figures. This is the only level of accuracy that you can be sure of.
Ex. Find the area of an rectangle with a length of 82.6 cm and width of 63.45 cm .
A= 82.6 x 63.45
A= 5240.97 cm
A= 5240
This must be rounded to 5240 cm, because 82.6 only has only 3 significant figures, so the answer can only have 3 significant figures.
When adding or subtracting the answer can only be carried out to the decimal place of the number being added or subtracted that is carried out to the smallest decimal place.
Ex. 56.79 + 54.7 = 111.49
The answer must be rounded to 111.5 because 54.7 is only carried out to the tenths place.
*Do not round multi-step problems until the final answer, or your answer and another person’s answer will vary slightly.
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