1. Teaching the Metric System Sally B. Mitchell sallybchemistry.com For meaning and understanding

2. Identify the problem

4. Engineer a Solution to a problem with education 7 years of research Writing to learn Re-teach teachers (keep an open mind)

5. Numbers How many ways can you express this number? Three hundred million

6. Normal Notation 300,000,000

7. Scientific Notation 3 x 10 8

8. Engineering Notation 300 x 10 6

9. Metric Notation 300 M

10. Ways to express quantities Written notation (three hundred million) Number notation (300,000,000) Scientific notation ( 3 x 10 8 ) Engineering notation ( 300 x 10 6 ) Metric notation ( 300 M) Infinite number of other ways ( 30 x 10 7 )

11. What is a metric prefix? Quantity? Number? Symbol?

12. Why do we even use prefixes? Easier to write Easier to say Easier to manipulate It is concise

13. Do you know your prefixes? 10 -12 10 -9 10 -6 10 -3 10 0 10 3 10 6 10 9 10 12 p n μ m k M G T

14. Try another 0.000 000 000 032 Notice the spaces between groups of 3 numbers 3.2 x 10 -11 (Scientific Notation) 32 x 10 -12 (Engineering Notation) 32 p (Metric Notation)

15. What is the appropriate prefix for this quantity? The time was 45,000,000,000 seconds 45 Gs The distance between the objects was 0.000 050 m 50 μm

16. Why change the prefix? Yet, we assess the student’s ability to CONVERT from kilometers to nanometers on the first day of class! Convert 2 km to nm REALLY? Is this a conversion?

17. Sound Mathematical Principles 2 x 10 3 m

18. Multiplicative Identity and Multiplicative Inverse 2 x 10 3 x ( ) m 10 -9 10 9 x

19. Associative Law and Law of Exponents (2 x 10 3 x 10 9 ) x 10 -9 m 2 x 10 12 x 10 -9 m

20. Substitution of Symbol 2 x 10 12 nm

21. Check it 2 km = 2 x 10 12 nm ?

22. Look at only the quantity 2 k = 2 x 10 12 n ? 2 x 10 3 = 2 x 10 12 x 10 -9

23. Calculate the density of radon gas at STP Mass = 450 mg Volume = 50 mL Express your answer in g/L Density = 9 g/L

24. 100 % confidence Teach about numbers and different ways to express Review Scientific Notation Introduce Engineering Notation Discuss prefixes Remember to develop “Prefixes are symbols” Challenge your students to express quantities using different symbols

25. Remember NO DIMENSIONAL ANALYSIS No tricks No centi Groups of 3 (300,000,000 0.000 000 000 032)

26. What is a MOLE? 6.02 x 10 23 ? 602 x 10 21 ?