## Chemistry 9th Edition

a) $212.2 + 26.7 + 402.09 = 640.99$ This becomes $641.0$ because the first two numbers restrict the final answer to one decimal place. b) $1.0028 + 0.221 + 0.10337 = 1.32717$ This becomes $1.327$ because the second number restricts the final answer to three decimal places. c) $52.331 +26.01 - 0.9981 = 77.3429$ This becomes $77.34$ because the second number restricts the final answer to two decimal places. d) $2.01 \times 10^2 + 3.014 \times 10^3 = 3215$ This becomes $3220$ because the first number is limited to two decimal places. e) $7.255 - 6.8350 = 0.42$ This becomes $0.420$ because the value is accurate to the third decimal place, as shown by the first number.