1. Lesson 9 Contents Example 1Identify Precision Units Example 2Identify Significant Digits Example 3Identify Significant Digits Example 4Add Measurements Example 5Multiply Measurements

2. Example 9-1a Identify the precision unit of the thermometer. Answer: There are 5 spaces between each 10°mark, so the precision unit is of 10 degrees or 2 degrees.

3. Example 9-1b Identify the precision unit of the ruler. Answer: inch

4. Example 9-2a Determine the number of significant digits in the measure 5,000 feet. Answer: 1 significant digit

5. Example 9-2b Determine the number of significant digits in the measure 21.0 miles. Answer: 3 significant digits

6. Example 9-3a Determine the number of significant digits in the measure 315.05 ounces. Answer: 5 significant digits

7. Example 9-3b Determine the number of significant digits in the measure 35.006 centimeters. Answer: 5 significant digits

8. Example 9-4a MAIL Venita took four packages to the post office. They weighed 1.27 pounds, 3.45 pounds, 0.524 pound, and 2.7 pounds. Write the combined weight of her mail using correct precision. Answer: The combined weight of the packages is about 7.9 pounds. 1.27 0.524 3.45 7.944 2 decimal places 3 decimal places 1 decimal place The least precise measurement has 1 decimal place, so round the sum to 1 decimal place.

9. Example 9-4b DELI Veric bought 1.5 pounds of turkey, 0.75 pound of roast beef, 2.4 pounds of ham, and 0.5 pound of salami. Write the combined weight of the lunch meat that Veric bought using correct precision. Answer: 5.2 lb

10. Example 9-5a Use the correct number of significant digits to find the volume of the cylinder. Use 3.14 for pi. Volume of a cylinder Answer: Round the answer, 187.0017188, so that it has 2 significant digits. The volume of the cylinder is about 190 cubic inches. The height of the cylinder has the least number of significant digits, 2.

11. Example 9-5b Use the correct number of significant digits to find the volume of the rectangular prism. Answer:

12. End of Lesson 9