Chemistry 5.0
Significant Digits
Name _________________________________
Date ___________________ Period ________
Counting: Determine the number of significant digits in each of the following measurements.
1.
6.751 g
_____
6.
43.07 cm
_____
2.
0.157 kg
_____
7.
2.690 g
_____
3.
28.0 mL
_____
8.
0.002300 mg _____
4.
2500 m
_____
9.
2500.0 cm
_____
5.
0.070 g
_____
10.
0.189 mL
_____
Rounding: Round #11-15 to 2 significant digits
Round #16-20 to 3 significant digits
11.
30.07 g
________
16.
144.07 g
__________
12.
0.106 cm
________
17.
40.319 hg
__________
13.
0.0067 g
________
18.
48.57193 daL __________
14.
26.509 cm
________
19.
0.1209 m
__________
15.
0.0230 cm
________
20.
54.52 mL
__________
Calculations: Perform the following calculations and round to the proper number of significant digits
based on the adding/subtracting and multiplying/dividing rules learned in class.
21. 3.20 g + 0.03 g _________________ 22. 4302 g  0.8 cm3
___________________
23. 100. cm – 1.6 cm _________________
___________________
25. 100 s – 1.3 s
24. 5.7 cm x 0.20 cm
_________________ 26. 10.2 s  0.4 s
___________________
Corrections: The following problems have been performed on a calculator. Rewrite the answers so that
they have the correct precision. One answer is correct.
1. 1.25 g x 8.6 C = 10.75 gC
________________
2. 100.00 g 
________________
25.0 mL = 4 g/mL
3. 500.00 cm x 40.00 cm = 20,000 cm2
________________
4. 38 cm + 5.100 cm + 4.13 cm = 47.23 cm
________________
5. 716.55 g – 0.005 g = 716.545 g
________________
6. 28.00 g  85.2 cm3 = 0.3286385 g/cm3
________________
7. 8.000 km – 0.54 km = 7.46 km
________________
8. 23.18 m + 6.819 m = 29.999 m
________________
Calculations: Express your answers with the correct number of significant digits.
9.
16.5
+
10.
13.25
11.
23.27 –
12.
13.57 –
13.
2.6
14.
8
4.37
=
______________
9.6
=
______________
12.058
=
______________
6.3
=
______________
×
3.78
=
______________
6.54
×
0.37
=
______________
15.
0.58
÷
2.1
=
______________
16.
39
÷
24.2
=
______________
17.
27.68 –
14.369
=
______________
18.
0.085
______________
19.
0.0853 +
20.
0.075
+
×
÷
10.00
+
+
0.050
×
0.655 =
0.0547
+
0.0370
0.030
+
=
0.00387
=
______________
______________