## Addition and subtraction of measured numbers

When you compute a result from several measured numbers, each of which has a certain accuracy, you should give the result with the correct number of significant figures. Addition and subtraction When numbers are added or subtracted, the number of decimal places in the result should equal the smallest number of decimal places of any term in the sum or difference. Examples 1.33 + 0.33 = 1.66 1.33 + 0.67 = 2.00 1.33 + 0.033 = 1.36 1.33 + 0.0033 = 1.33 1.33 + 0.0055 = 1.34 1.33 - 0.33 = 1.00 1.33 - 0.033 = 1.30 1.33 - 0.0033 = 1.33 1.50 times 10^2 + 1.235 times 10^2 = 1.74 times 10^2 1.50 times 10^2 + 1.235 times 10^3  =0.150 times 10^3 + 1.235 times 10^3 =1.385 times 10^3 1.50 times 10^2 + 1.235 times 10^4  =0.0150 times 10^4 + 1.235 times 10^4 =1.250 times 10^4 1.50 times 10^2 + 1.235 times 10^5  =0.00150 times 10^5 + 1.235 times 10^5 =1.237 times 10^5