Question

add or subtract the following measurements. be sure each answer you enter contains the correct number of significant digits.
19.7 ml + 2.520 ml = ml
19.60 ml + 7.800 ml = ml
16.800 ml - 9.6 ml = ml

Explanation:

Step1: Add 19.7 mL and 2.520 mL

When adding or subtracting, we consider the least number of decimal places. 19.7 has one - decimal place.
$19.7+2.520 = 22.220\approx22.2$ mL

Step2: Add 19.60 mL and 7800 mL

19.60 has two - decimal places, but 7800 has no decimal places.
$19.60 + 7800=7819.60\approx7820$ mL

Step3: Subtract 9.6 mL from 16.800 mL

16.800 has three - decimal places and 9.6 has one - decimal place.
$16.800−9.6 = 7.200\approx7.2$ mL

Answer:

22.2 mL
7820 mL
7.2 mL