1. Measuring

2. Accuracy v. Precision pg. 8 Precision - how closely the measurements match each other. Instruments that measure using more decimals are more precise. Accuracy – how closely the measurement matches the true or accepted value.

3. Accurate Precise

4. Accurate Precise

5. Accurate Precise

6. Accurate Precise

7. Accurate Precise

8. How To Read Scientific Instruments 1) Record the _______ digit on the instrument. 2) Then _______________ the last digit.

9. Significant Figures Measuring devices are not perfect. Human measurements always have a small degree of uncertainty All digits known for certain plus the last digit which is an estimation. Each digit in the measurement is called a significant figure.

10. How to Read a Graduated Cylinder Sit the graduated cylinder on a level surface. Lower your eyes to the level of the liquid (called the meniscus). Take your reading from the bottom of the meniscus. Count all of the digits you are sure of. Add the last digit that you estimate.

11. Quiz page13 Number your paper 1 to 15.

12. 1) Measuring Length A.2 cm B.19 cm C.1.95 cm D.1.95238 cm

13. 2) Measuring Length A.10cm B.1.1cm C.1.05cm D.1.526cm

14. 3) Measuring Length A.17 cm B.17.5 cm C.18.0 cm D.17.5082 cm

15. 4) Measuring Length A.4cm B.4.3cm C.4.30cm D.4.3057cm

16. 5) Measuring Length A.12 cm B.12.0 cm C.12.7 cm D.12.0953 cm

17. 6) Measuring Liquids The meniscus is the curve in the upper surface of a liquid close to the surface of the container or another object, caused by surface tension. It can be either convex or concave. surface tensionconvex or concave Is this meniscus convex or concave? 6) _________________ For questions 7 to 12, measure the amount of liquid in each graduated cylinder by reading the bottom of the meniscus.

18. 7) Measuring Liquid Volume A.10ml B.10.3ml C.11.5ml D.13.0ml

19. 8) Measuring Liquid Volume A.266 ml B.287 ml C.290 ml D.294 ml

20. 9) Measuring Liquid Volume A.52 ml B.53 ml C.54.5 ml D.52.8 ml

21. 10) Measuring Liquid Volume A.80 ml B.80.0 ml C.81.0 ml D.79.0 ml

22. 11) Measuring Liquid Volume A.2.8 ml B.2.80 ml C.2.90 ml D.2.9 ml

23. 12) Choose the correct answer. Amelia measured the amount of liquid her thimble would hold. She wrote down three numbers: 4.4ml, 4.3ml and 4.5ml. Pick the letter that best describes her measurements based on the actual amount of liquid shown in the graduated cylinder. A.Accurate B.Precise C.Both Accurate and Precise D.Neither Accurate nor Precise

24. 13) Measuring Solids A.625.62g B.26.57g C.265.73 D.526.6g

25. 14) Measuring Solids A.373.33g B.734.33g C.374.33g D.373.3g

26. 15) Measuring Solids A.222.50g B.221.50g C.221.5g D.221.0g

27. Answers to Quiz 1)C 1.95cm 2)C 1.05cm 3)B 17.5cm 4)C 4.30cm 5)B 12.0cm 6)Concave 7)C 11.5ml 8)D 294ml 9)D 52.8ml 10)B 80.0ml 11)B 2.80ml 12)B Precise 13)C 265.73g 14)A 373.33g 15)B 221.50g