Question

Perform the followingmathematical operation andreport the answer to theappropriate number ofsignificant figures.7.273 - 12.37 = [?]Enter

Answer 1

When we perform an addition or a subtraction of numbers and we want the appropiate number of significant figures we need to follow the steps:

0. Count the number of significant figures in the decimal portion of each number in the problem

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1. Add or subtract in the normal fashion

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2. Your final answer may have no more significant figures to the right of the decimal than the least number of significant figures in any number in the problem.

Let's follow this steps to solve the problem.

The first number (7.273) has three significant figures after the decimal point; the second number (12.37) has two significant figures after the decimal point.

Now we perform the subtraction:

$7.273-12.37=-5.097$

Now, since the least number of significant figures for the numbers is two, this means that our result has to have only two significant figures after the decimal point; since the third significant figure after the decimal point is greater than 7 we round up the second significant figure after the decimal point but since this is nine we round up the first significant figure after the decimal point.

Therefore the correct result will be -5.1