1. TOPIC: Significant Figures in calculations AIM: How do we add, subtract, multiply and divide measurement in significant figures?
DO NOW: ( 5 mins ) 1. 2.

2. Adding and Subtracting
TOPIC: Significant Figures in calculations AIM: How do we add, subtract, multiply and divide measurement in significant figures?
Adding and Subtracting
Line up the decimal points and add/subtract the #s
Final answer is rounded off with the least number of decimal places.
25.2 cm cm
25.2 cm cm
26.54 cm
answer one decimal place
one decimal place
two decimal places

3. answer 66.12 mL 2 decimal places
TOPIC: Significant Figures in calculations AIM: How do we add, subtract, multiply and divide measurement in significant figures?
Sample Problem:
mL mL mL mL mL
answer mL 2 decimal places
three decimal place
two decimal places

4. Multiplying and Dividing
TOPIC: Significant Figures in calculations AIM: How do we add, subtract, multiply and divide measurement in significant figures?
Multiplying and Dividing
Line up the decimal points and multiply/divide the #s
Final answer is rounded off with the least number of significant figures.
9.23 kg x 0.16 kg
9.23 kg
X0.16 kg kg
answer 1.5 kg 2 S.F.
3 S.F.
2 S.F.

5. Learning Check A. 235.05 + 19.6 + 2.1 = B. 58.925 - 18.2 =
TOPIC: Significant Figures in calculations AIM: How do we add, subtract, multiply and divide measurement in significant figures?
Learning Check
In each calculation, round the answer to the correct number of significant figures.
A =
B =
C X 4.2 =
D ÷ =
E X =
X 0.060

6. TOPIC: Significant Figures in calculations AIM: How do we add, subtract, multiply and divide measurement in significant figures?
HOMEWORK
In each calculation, round the answer to the correct number of significant figures.
A =
B =
C X 1.2 =
D ÷ =
E X =
X 0.160