#### Answer

a) 641.0
b) 1.327
c) 77.34
d) 3220
e) 0.420

#### Work Step by Step

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.