123 mm = _________ dm Question of the Day 1 m 10 dm 123 mm = X X 1000

- scientists repeat experiments and AMOUNT MATTERS! Significant Figures What is a sig. fig.? - A measured digit Why is it important to understand what is a certain measurement and what is not? - scientists repeat experiments and AMOUNT MATTERS!

Significant Figure Rules Think Certainty Rules governing significance: Non-zeros are always Significant (1, 2, 3, 4…). 2. Zeros between non-zeros (sig. figs.) are Always Significant (707).

Significant Figure Rules Rules governing significance: 3. A final zero or trailing zeros in the decimal portion ONLY are significant (0.010200). 4. Place holders are not significant (0.004, 400) are significant are NOT significant

Significant Figure Rules 4. Place holders are not significant (0.004, 400) Zeroes placed before other digits are not significant; 0.046 has two significant digits. Zeroes at the end of a non-decimal # are significant only if there is a decimal point (100.). They are NOT sig. if there is not a decimal point (100)

Significant Figure Rules Another approach Non-zeros are Always Significant (1, 2, 3, 4…) 2. Zeros between non-zeros are Always Significant (707)

Left of the decimal Right of the decimal Another approach 3. Other Zeros Left of the decimal Right of the decimal Is the zero by its self Is there a non-zero If yes = Not sig. anywhere to the left If no is there a dec. – if yes = sig. Pt. to the right if yes = Significant 0.006 10.0506 2020 - 1 - 6 - 3

Left of the decimal Right of the decimal Another approach 3. Other Zeros Left of the decimal Right of the decimal Is the zero by its self Is there a non-zero If yes = Not sig. anywhere to the left If no is there a dec. – if yes = sig. Pt. to the right if yes = Significant 200 20.0 200. - 1 - 3

Significant Figure Practice 7.0080 0.00640 70.0 7.07001

To Make a Student Account for Portal:   Go to sburg.org. Click blue Sapphire link (bottom right). Click Community Portal Application and Acceptable Use Policy Form (right side). Keyword = mountie Scroll down and change drop down to Student Account. Click Yes and then continue. Fill out application…

Explain how you convert from Celcius to Kelvins. CP Question of the Day Explain how you convert from Celcius to Kelvins. 2. Convert 4500 micrograms to milligrams. Day 6 10-21

Practice How many sig. figs.? 72010 710.00 0.006

Objectives / Essential Questions CP Objectives / Essential Questions How is certainty expressed in measurements and simple calculations?

Rules For Multiplying And Dividing With Sig. Figs. 1. Do the Math – Get an answer 2. Go Back to your original Numbers and Count Significant Figures 3. Use the least # of Significant Figures (from your original #s) For your answer 14

Rules For Multiplying And Dividing With Sig. Figs. 2 1 1. 20. * 10 = 200 = 200 2 3 2. 0.010 * 20.0 = 0.2 = 0.20 3 2 3. 10.0 / 5.5 = 1.8181…= 1.8

Significant Figure Rules To eliminate sig. figs. ROUND To add sig. figs. Use a dec. pt. OR add zeros

Practicing Multiplying And Dividing With Sig. Figs. 1. 2.00 * 1.0 = 2.0 = 4.0 2. 10.1 / 2.5

Significant Figure Rules Practice Assignment Notebook Checks

Question of the Day 1. Convert 1,200 km to dm. 2. How many sig. figs.: 0.0170 700.010 3. Calculate with sig figs.: 21.3 * 10. Day 1 10-22

Significant Figure Rules What are the rules for multiplying and dividing?

Discussion partner review – it’s graded!!!

Rules For Adding And Subtracting With Sig. Figs. 1. Do the Math – Get an answer 2. Go Back to your original Numbers and find the last significant digit (farthest to the right) – underline it in each original number. 3. Find the underlined digit farthest to the left and round your answer to that place

Rules For Adding And Subtracting With Sig. Figs. 1. 20. + 10 = 30 = 30 2. 0.010 + 20.0 = 20.01 = 20.0 3. 10. - 5.5 = 4.5 = 5

Practice Adding And Subtracting With Sig. Figs. 1. 41. + 20 = 61 = 60 2. 0.010 - 12.34 = - 12.330 = - 12.33

Significant Figure Rules Practice Packet