Counting Significant Figures (Sig Figs)
Name: ________________________
Date:_____________
pearsongreatpath.wikispaces.com
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.
Practice Problems: Identify the number of significant digits in each of the following
1) 23.7 x 10-2 cm 2) 1.4 x 107 L
3) 4.293 x 104 km 4) 705 seconds
5) 600 cm
6) 4301.0 GHz
8) 40280 daL
10) 8 students
Answers 1) 3
7) 0.00056 dg
2) 2
3) 4
4) 3 (it is possible to 705.2 seconds)
9) 24 Megapixels
5) 1
6) 5
7) 2
8) 4
9) 2
10) Unlimited
MORE Practice Problem: Identify the number of significant digits in each of the following
1) 192 rulers
2) 5,400 km
3) 100.0 minutes 4) 7.29 years
5) 0.000004 m
6) 8,000,000 m/s
7) 0.010060 hL
8) 10.02 cg
10) 357 dam
Answers 1) Unlimited
2) 2
3) 4
4) 3
5) 1
6) 1
9) 52 teeth
7) 5
8) 4
9) Unlimited
10) 3
EVEN MORE Practice Problem: Identify the number of significant digits in each of the following
1) 409 cars
2) 51.050 L
3) 0.000007
4) 6.52 x 10-5 kg
5) 5,000 staples
6) 738.000 Mm
7) 7.20 x 108 kL
8) 31 light years
9) 30 m
10) 16
Answers: 1) Unlimited
2) 5
3) 1
4) 3
5) unlimited
6) 6
7) 3
8) 2
9) 5
10) Can not determine – no units listed
HOME WORK - How many significant figures are in each of the following numbers?
NOTE: Be careful of the units, some of them are TRICKY 
1)
5.40 m ____
11) 1.2 x 103 mice ____
2)
210 seconds ____
12) 0.00120 minutes ____
3)
801.5 kg ____
13) 30.0 L ____
4)
4,000 mm ____
14) 9.010 x 10-6 kg ____
5)
101.0100 kL ____
15) 2,370.0 light years ____
6)
11 dogs ____
16) 6.200 x 10-4 km ____
7)
27 dag ____
17) 18 GHz ____
8)
1500 rulers ____
18) 27
9)
.0007 km ____
19) 3 x 100 m ____
10) 0.0300 mL ____
____
20) 200. L ____