Practice Problems for Significant Figures
RULE -1: If the decimal is Present: Find the first non zero on the left, then count all digits to the RIGHT
If the decimal is Absent: Find the first non zero on the right, then count all digits to the LEFT
RULE-2: Every digit in scientific notation is Significant
RULE-3: Any number that is counted is an EXACT number and has UNLIMITED significant digits.
How many significant figures do the following numbers have?
1)
1234 m ____
2)
8)
3.4 x 104 g_____
9)
9.0 x 10-3 cm_____
0.023 L_____
3)
890 kg_____
4)
10)
9.010 x 10 g____
11)
0.00030 hL_____
12)
1020010 mg_____
9010.0 cm_____
6)
1090.0010 g_____
7)
0.00120 km_____
1000 mm_____
15)
918.010 L_____
16)
0.0001 kg_____
17)
0.00390 kL_____
18)
8120 cats_____
19)
7.991 x 10-10 g____
20)
72 students_____
-2
91010 m _____
5)
14)
13)
780. cm_____
Solutions to the “How many significant figures”
1) 4
11) 2
2) 2
12) 6
3) 2
13) 3
4) 4
14) 1
5) 5
15) 6
6) 8
16) 1
7) 3
17) 3
8) 2
9) 2 10) 4
18) unlimited
19) 4
20) unlimited
Review Game for Sig Figs http://science.widener.edu/svb/tutorial/sigfigurescsn7.html
Rule for Multiplication & Division = Least number of Sig Figs
Rule for Addition & Subtraction = Least number of decimal places (highest value)
Review Questions for Calculations with Sig Figs http://www.sciencegeek.net/Chemistry/taters/Unit0Sigfigs.htm
Perform the following calculations and round according to the rule above.
1) 8.20 + 2 =
4) 53.4028 - 14 =
Answers 1) 10
2) 57
4) 38 / 7 =
1)
2)
3)
4)
3) 42.828 + 67.4629 =
5) 39.3 - 0.804 =
6) 91.68 - 19.1 =
3) 110.291
1) 7.6 x 21.9 =
Answers: 1)170
2) 13.59 + 23.25 + 20 =
2)700
4) 39
2) 31 g/mL
3) 5.00009 x 0.06 =
5) 500 009 / 17.000 =
6) 500 000 / 5.002 =
3)0.3
3) 62 J/s
http://www.chemfiesta.com
6) 72.6
2) 2.15 x 3.1 x 100 =
4)5
334.54 grams + 198 grams = ____________
34.1 grams / 1.1 mL = __________________
2.11 x 103 joules / 34 seconds = __________
0.0010 meters – 0.11 m = ______________
1) 533 grams
5) 38.5
4) -0.11 m
5)29 412
5)
6)
7)
8)
6)100 000
349 cm + 1.10 cm + 100 cm = ______________
450 meters / 114 seconds = ________________
298.01 kilograms + 34.112 kilograms = _______
84 m/s x 31.221 s = ___________________
5) 500 cm
6) .9 m/s
7) 332.12
8) 2600 m