Presentation on theme: "“How do you evaluate data and conclusions to determine the validity of"— Presentation transcript:
1“How do you evaluate data and conclusions to determine the validity of Essential Question“How do you evaluate dataand conclusions todetermine the validity ofresearch?”
2Objectives1. Define SI base units for time, length, mass and temperature.2. Explain how adding a prefix changes a unit.3. Compare the derived units for volume and density.4. Express numbers in scientific notation.
3Objectives 5. Define and compare accuracy and precision; 6. Use significant figures and rounding to reflect the certainty of data;7. Use percent error to describe the accuracy of experimental data;8. Interpret graphs.
4Significant Figures 1. All digits that are not zero, are significant. 45678 5sf2. Zero’s between non – zero digits and significant numbers.7804 4sf 7 sf
5Significant Figures3. Zeros to the left of the 1st non – zero digit are not significant. 2 sf4. Zeros to the right of a decimal point are significant if the right of a decimal point aresignificant if they are at the end of the number. 4 sf777.0 4 sf
6Significant Figures 5. Always assume zeros at the end of a number to be non-significantCompare 3400 and3400 has 2 sig fighas 5
7Addition and Subtraction When adding or subtracting numbers, the answer should have as many places of decimal as the smaller or smallest place of decimal in the numbers being added or subtracted.Example:= 60.4 NOTshould only have 1 place of decimal.
8Multiplication and Division When multiplying or dividing numbers, the answer should have significant figures as many as the least number of significant figures in the numbers being multiplied or divided.For example: x 1.2 x 2.23 = 65 NOT
9Division Example 465.75/45.6 must have 3 significant figures. Therefore, /45.6 = 10.2NOT ….
10Combined Multiple Operations If a problem combines addition or subtraction and multiplication or division, apply rules separately.That is, use places of decimal for addition and subtraction and significant figures to multiplication and division portion of the problem.
11Combined Multiple Operations Example(9.12 – 8.9)/8.9 = 0.2/8.9 = 0.02Note: (9.12 – 8.9) = 0.2 based on 1 pld0.2/8.9 = 0.02 based on 1 sf in 0.2