1. Significant Figures Part 2 Problem Solving Applications

2. Multiplying & Dividing When multiplying or dividing, your answer may only show as many significant digits as the multiplied or divided measurement showing the least number of significant digits.

3. Examples 22.37 cm x 3.10 cm x 85.75 cm = 5946.50525 cm 3 = 5950 cm 3 (3.0 x 10 5 m 2 )/(2.45 x 10 3 m) = 122.4489…m = 120 m

4. More Examples 5000 g / 4.25 g = 1176.470588 = 1000 2500 N x 40. N = 100000 N 2 = 1.0 x 10 5 N 2

5. Adding and Subtracting When measured quantities are used in addition or subtraction, the uncertainty is determined by the absolute uncertainty in the least precise measurement (not by the number of significant figures). Sometimes this is considered to be the number of digits after the decimal point.

6. Examples 3.45 cm + 8.1 cm = 11.55 cm = 11.6 cm 31.492 g – 30.9481 g =.5439 g =.544 g 685 N + 3.9 N = 688.9 N = 689 N

7. More Examples 1060 L – 997.2 L = 62.8 L = 60 L 890 Kg + 0.874 Kg = 890.874 Kg = 890 Kg

8. Practice Problems 1.890 / 5.86 = 151.8771331 = 150 2.8.203 x 4.3 = 35.2729 = 35 3.300 x 52 = 15600 = 20000 4.40. x (6.02 x 10 23 ) = 2.408 x 10 25 = 2.4 x 10 25 5.(3.50 x 10 2 ) / (8.2 x 10 3 ) = 0.0426829268 = 0.043 or 4.3 x 10 -2

9. Practice Problems 6.6.3.00 + 82.890 + 4.8 = 90.69 = 90.7 7.7.3.24 – 1.005 – 0.023 = 2.212 = 2.21 8.81.02 + 25 – 8.023 = 17.997 = 18 9.30 – 5.9 + 2.45 = 26.55 = 30 10.56.8 + 20. – 42.33 = 34.47 = 34