1. Significant Digits

2. I. Recognizing Sig. Digs on Instruments
Measuring is essential when collecting data
Precision (getting the same number each time) has a lot to do with uncertainty
To be precise (decrease uncertainty) you should measure:
Carefully and more than once
Estimate to one digit beyond the smallest mark on the instrument

3. II. Recognizing Sig. Digs on Paper
A. Basic Rules:
Any number 1-9 is considered significant
Zeros are significant if they:
Terminate the number to the right of the decimal
They are “sandwiched” between two significant digits

4. II. Recognizing Sig. Digs on Paper
B. Advanced Rules: Calculations
When Adding or Subtracting: your answer should be rounded to match the measurement with the LEAST no. of DECIMAL PLACES
When Multiplying or Dividing: your answer should be rounded to match the measurement with the LEAST no. of SIGNIFICANT DIGITS

5. I. Recognizing Sig. Digs on Instruments
Measuring is essential when collecting data
Precision (getting the same number each time) has a lot to do with uncertainty
To be precise (decrease uncertainty) you should measure:
Carefully and more than once
Estimate to one digit beyond the smallest mark on the instrument
PRACTICE/EXAMPLES:

6. I. Recognizing Sig. Digs on Instruments
PRACTICE/EXAMPLES:
How many sig digs?
a.) 3.57
b.) 288
c. )20.8
d.) 0.01
e.)0.010
f.)0.0100
A. Basic Rules:
Any number 1-9 is considered significant
Zero are significant if they:
Terminate the number to the right of the decimal
They are “sandwiched” between two significant digits

7. II. Recognizing Sig. Digs on Paper
B. Advanced Rules: Calculations
When Adding or Subtracting: your answer should be rounded to match the measurement with the LEAST no. of DECIMAL PLACES
When Multiplying or Dividing: your answer should be rounded to match the measurement with the LEAST no. of SIGNIFICANT DIGITS
PRACTICE/EXAMPLES:
a) mL mL = mL
calculator value
1.23 cm * cm = cm2