Sig Fig Calculations Safety Activity Objectives Explain why

Sig Fig Calculations Safety Activity

Objectives: • • • Explain why significant figures are important to making measurements. Apply the rules for significant figures to calculations. Apply the safety rules to a safety activity challenge. • Informal Assessment: • Monitoring student interactions and questions as they complete the measurement lab and significant figures practice • Formal Assessment: • Analyzing student responses to measurement lab and significant figures practice • Common Core Connection • • • Use appropriate tools strategically Attend to precision Make sense of problem and persevere in solving them

Lesson Sequence Evaluate: Warm-Up Explain: Significant Figure Notes Elaborate: Significant Figures Calculation Practice Engage/Elaborate: Safety Activity Challenge Evaluate: Exit Ticket

Warm - Up Determine the number of significant figures in the measured values below ◦ 5100 ◦ 0. 000720 ◦ 41004 What technique should be used when mixing acid and water in a lab setting? What protocol should be followed if a chemical gets into your eye during lab?

Objectives: Today I will be able to: • Explain why significant figures are important to making measurements. • Apply the rules for significant figures to calculations. • Apply the safety rules to a safety activity challenge.

Homework Finish Safety Challenge WS Study for Significant Figures Quiz on Friday, September 5

Agenda Warm-Up Significant Figures Notes Significant Figures Calculations Practice Safety Activity Challenge Exit Ticket

Significant Figure Notes

What’s the SIGnificance?

How many decimals can each ruler be read to?

What volume of water is in the graduated cylinder?

Which balance do you think costs the most and why?

Significant Figure Calculations

Atlantic Pacific Rule

Atlantic Pacific Rule • If a decimal point is Present as in 52. 3 km, count from the “Pacific Side” from the first nonzero digit to the end. Meaning, count from the left side of the number - 52. 3 has 3 sig figs - How many sig figs in. 0093077 - There are 5 sig figs (start counting at 9)

Atlantic Pacific Rule • • If the decimal point is Absent, as in 1530 g, count from the Atlantic Side beginning with the first nonzero digit and going to the end, counting any zero as significant. This means start from the right - 1530 g has 3 sig figs How many sig figs in 190, 542, 100 ml - There are 7 sig figs

Examples • . 0026702 m -5 • 19. 0750 kg -6 • 25, 000, 000 mm -2 • 1, 908, 150 -6 • 520 ml -2 • . 0102 ns -3 L

Sig Fig Calculations • • • You cannot be more precise than your least precise measurement In multiplication and division, the measurement with the smallest number of sig digits determines how many digits are allowed in the final answer If you have several steps, carry the extra digits. Only the final answer is rounded

Examples 6. 15 m x 4. 026 m = ? - 6. 15 m has 3 sig figs - 4. 026 m has 4 sig figs - Your answer can only have 3 sig figs - 24. 7599 m 2 24. 8 m 2

Examples • . 03287 g x 45. 2 g = ? -. 03287 g has 4 sig figs - 45. 2 g has 3 sig figs - Your answer can only have three sig figs - 1. 485724 g 1. 49 g

Final Note When doing calculations with significant figures, conversion factors do not figure in Counts and defined numbers are EXACT and have no uncertain digits Example: if you say there are 6 people in your family it is a counted number and is considered certain. There are not 6. 1 people in your family Example: 12 inches = 1 foot is defined – do not use significant figures. 1 foot will never be 11. 99 inches. In both cases, significant figures do not apply

Significant Figures Calculation Practice Complete the practice at your desk.

Safety Activity Challenge Work in your rows to complete the challenge

Exit Ticket Complete the calculation to the correct number of sig figs. ◦ 4. 21 X ◦ 5. 126 – Icebreaker: 5. 5270 = 2. 2 = ◦ If you could turn yourself into something different (car, animal, plant, etc) for one week, what would it be? ◦ Would you rather be 4 inches tall or 100 ft tall?