4. Why do we use significant digits?
• Because any measurement involves errors
5.
6. What is the difference between 26kg and
26.0kg? Accuracy!
Finding significant digits
Rule 1:
• Look for a decimal point.
• e.g. 26kg. NO decimal point
• e.g. 26.0kg.YES decimal point
• e.g. 26.0000kg.YES
7. Rule 1: Look for decimal point
Rule2: if there is no decimal point, the
zeros at the end do not count.
• 26kg
• 260kg
• 2600000000kg
• (all have 2 significant digits)
8. Rule 1: Look for decimal point
Rule2: if there is no decimal point, the
zeros at the end do not count.
Rule3: if there is a decimal point, the
zeros at the beginning do not count.
• 0.003kg (1 significant digit)
• 0.0030kg (2 significant digits)
• 0.0030000kg (5 significant digits)
• 1.0030kg (5 significant digits)
9. .0026701 kg
2.6701 kg
2.67010 kg
2.670100 kg
10.0550 kg
3500 m
1,809,000 L
10. 3.052 m X 2.10 m X 0.75 m =
4.8069 m3
Which number has the least number of
significant digits?
The answer has the same # of significant
digits as the number with the smallest #.
4, 3, 2. Answer = 4.8069 m3
.
4.8 m3
12. 32,700
• 3.27 x 104
1,024,000
• 1.024 x 106
.0047100
• 4.71 x 10-3
13. A. Find the number of significant digits
in:
• a) 400 b) 4000 c) 400.1 d) 400.10
• e) 0.001 f) 0.0010
B. Scientifically notate:
• a) 0.0358
• b) 358,000