Practice - Scientific Notation, Rounding, and Significant Figures

1. There are 1,760,000,000,000,000,000,000 molecules in 1 gram of sucrose (ordinary sugar). Use scientific notation to express this number to four significant figures. Answer.
2. Use scientific notation to indicate the diameter of the sodium atom (0.000000000388 meters). Answer.
3. The diameter of the earth at the equator is 7,926.381 miles. Answer
   1. Round this measurement to four significant figures.
   2. Round this measurement to two significant figures.
   3. Round this measurement to six significant figures.
   4. Express this measurement in scientific notation.
   5. Convert this measurement to kilometers. Express the result in scientific notation.
4. Are each of the following measured numbers or exact numbers: Answer
   1. number of inches in a mile
   2. diameter of a dime
   3. mass of a 12-oz bag of tortilla chips
   4. number of ounces in a pound
   5. number of micrometers in a kilometer
   6. number of inches in a kilometer
   7. mass of a baseball
   8. number of seconds in a year
   9. temperature of the sun's surface
   10. number of pages in your textbook
   11. surface area of a penny
   12. number of mL in a cubic foot of water
5. What is the number of significant figures in each of the following measured quantities? Answer
   1. 122 g
   2. 0.002796 s
   3. 8.07 m
   4. 0.001040 L
   5. 5.77590 x 10^-4 cm³
   6. 3,480,200 s
   7. - 1.200°C
   8. 1.0800 x 10^-2 L
   9. 3.141 cm
   10. 1000. m
6. Do each calculation and express to the appropriate number of significant figures. Answer
   1. 1.23056 + 67.809
   2. 23.67 - 500
   3. 890.05 x 12.3
   4. 324.55 - 6104.5/22.3
   5. 285.3 x 10⁶ - 12.000 x 10³ x 22.8954
   6. 0.0045 x 30,000.0 + 283 x 12
   7. 869 x (1255 - 3.45 x 10³)
7. Express each of the following in scientific notation. Answer
   1. 2586
   2. 4957500
   3. 0.003870
8. Change each of the following from scientific notation to normal notation. Answer
   1. 4.87 x 10³
   2. 5.501 x 10⁶
   3. 2.540 x 10^-3