Practice - Scientific Notation, Rounding, and Significant Figures

4. Are each of the following measured numbers or exact numbers:
   1. number of inches in a mile - Answer: exact (5280)
   2. diameter of a dime - Answer: measured
   3. mass of a 12-oz bag of tortilla chips - Answer: measured
   4. number of ounces in a pound - Answer: exact (16)
   5. number of micrometers in a kilometer - Answer: exact (1 billion)
   6. number of inches in a kilometer - Answer: exact (because 2.54 cm/in, 100 cm/m, and 1000 m/km are all exact)
   7. mass of a baseball - Answer: measured
   8. number of seconds in a year - Answer: exact (for any single year, because 60 sec/min, 60 min/hour, 24 hours/day, 365 or 366 days/yr are all exact)
   9. temperature of the sun's surface - Answer: measured
   10. number of pages in your textbook - Answer: exact (you can count them)
   11. surface area of a penny - Answer: measured
   12. number of mL in a cubic foot of water - Answer: exact (because 1 mL/cm³, 2.54 cm/in, and 12 in/ft are all exact)