Significant Figures Significant Figure Rules 1 All Nonzeros

Significant Figures

Significant Figure Rules

1. All Nonzeros are significant. 523 g = 3 sig figs 3 4222 cm = 4 sig figs

2. All numbers between significant figures are significant. 4, 404 g = 4 sig figs 9. 005 mm = 4 sig figs 5, 000, 102 mg = 7 sig figs

3. All final zeros past the decimal are significant. 9509. 90 cm = 6 sig figs 52. 000 km = 5 sig figs

4. Zeros used solely as placeholders are NOT significant. 42, 000 L = 2 sig figs 42, 000. 00 L = 7 sig figs 0. 000802 g = 3 sig figs

Multiplication & Division Rules

1. Find the part of the problem with the least number of sig figs. 142 m x 1552 m x 0. 25 m = Which measurement has the least? 0. 25 m only has 2 sig figs.

2. Round your answer so it has that number of sig figs. 142 m x 1552 m x 0. 25 m = 55, 096= 55, 000

3. Units When multiplying, add the exponents. 142 m x 1552 m x 0. 25 m = 55, 000 m 3 When dividing, subtract the exponents. 12 g 3 ÷ 6 g = 2 g 2 18 g ÷ 2 cm 3 = 9 g/ cm 3

Addition & Subtraction Rules

1. Find the least accurate measurement in the problem. 14. 3 g + 99 g + 40 g = 40 g is the least accurate measurement. It is rounded to the nearest 10

2. Make your answer match the least accurate measurement. 14. 3 g + 99 g + 40 g = 153. 3 g must be rounded to the nearest ten The answer is 150 g

More Examples 300 g - 193 g - 21. 2 g = 85. 8 Since 300 g is the least accurate measurement, your answer must be rounded to the nearest 100. The answer is 100 g

Examples cont. 14. 2 m + 12. 36 m = 26. 56 Since 14. 2 is the least accurate measurement, the answer must be rounded to the nearest tenth. 26. 6 m