Unit 11 Units of Measurements

1. Unit 11Units of Measurements

2. Unit 11Units of Measurements Units and Measuring

3. Different units can be used to measure the same quantities. It is important to use appropriate units. Some important units are listed below. 1 km 1 m 1 m 1 cm 1 tonne 1 kg 1 litre 1m3 1cm3 = = = = = = = = = 1000 100 1000 10 1000 1000 1000 1000 1 m cm mm mm kg g ml litres ml

4. What would be the best units to use when measuring the following: • The distance between Negril and Kingston • The width of a watch face • The mass of a person • The mass of a letter • The mass of a truck • The volume of medicine in a spoon • The volume of water in a swimming pool km cm or mm kg g tonnes ml m3

5. 400 4000 3∙11 3110 1∙5 150 862 8620

6. Unit 11Units of Measurements You have finished viewing: Units and Measuring

7. Unit 11Units of Measurements Upper and Lower Bounds

8. Measurements are not exact If the length of a line is given as 11mm, then its length, in mm, lies between: Note that the lower bound is less than or equal to the length whereas the upper bound is strictly greater than the length 10∙5 ≤ length < 11∙5

9. Example A line is measured as 12∙7cm State the range of values within which its real length, in cm, must lie. Solution 12∙65 ≤ 12∙7 < 12∙75

10. B A Area = cm2 12 Area = cm2 10

11. C D Area ≈ cm2 14∙5 Area = cm2 12∙5

12. E Area ≈ cm2 22

13. Unit 11Units of Measurements You have finished viewing: Upper and Lower Bounds