1. Practice: 1) How many millimeters are in 4 m? Determine the possible conversion factors: The two units in this problem are m and mm, if 1 m = 1000 mm (10 3 mm ), then or 4 m x = 4 x 10 3 mm Multiply when converting from larger to smaller units. (4 000 mm)

2. Practice: 2) How many meters are in 54 cm? Determine the conversion factors: The two units in this problem are m and cm, & 1 m = 100 cm, then or 54 cm x = 0.54 m Divide when converting from smaller to larger units.

3. Giga (G) ---------- 10 9 Mega (M) --------- 10 6 Kilo (k) ----------- 10 3 Hecto (h) --------- 10 2 Deca (da) --------- 10 1 BASE UNIT (m,L,g,etc) Deci (d) ---------- 10 -1 Centi (c) ---------- 10 -2 Milli (m) ---------- 10 -3 Micro (μ) --------- 10 -6 Nano (n) --------- 10 -9 Pico (p) --------- 10 -12

4. Practice: 3) How many decaliters are in 3 kiloliters? Determine the possible conversion factors: The two units in this problem are daL and kL. 1 kL = 10 2 daL (because 10 3-1 = 10 2 ). or 3 kL x = 3 x 10 2 daL Multiply when converting from larger to smaller units. ( 300 daL)

5. Practice: 4) How many nanograms are in 25 decigrams? Determine the possible conversion factors: The two units in this problem are ng and dg. 1 dg = 10 8 ng (because 10 -1-(-9) = 10 -1+9 = 10 8 ). or 25 dg x = 25 x 10 8 ng Multiply when converting from larger to smaller units. = 2.5 x 10 9 ng

6. Practice: 4) How many decigrams are in 25 nanograms? Determine the possible conversion factors: The two units in this problem are ng and dg. 1 dg = 10 8 ng (because 10 -1-(-9) = 10 -1+9 = 10 8 ). or 25 ng x = 25 x 10 -8 dg Divide when converting from smaller to larger units. = 2.5 x 10 -7 dg

7. Giga (G) ---- 10 9 Mega (M) --- 10 6 Kilo (K) ----- 10 3 Hecto (h) --- 10 2 Deca (da) --- 10 1 BASE UNIT Deci (d) ---- 10 -1 Centi (c) ---- 10 -2 Milli (m) ---- 10 -3 Micro (μ) --- 10 -6 Nano (n) --- 10 -9 Pico (p) ---- 10 -12 Multiply Divide Shift the decimal point to the right Shift the decimal point to the left

8. Measurement and SI Units: Meter ( m ) for length Liter ( L ) for volume Gram ( g ) for mass Second ( s ) for time Kelvin ( K ) for temperature Joule ( J ) for energy Base units

9. Derived units are “built” from SI units: m 2 Ex. How can you calculate de area of the football field? How can you calculate de volume of this classroom? area volume m 3 ; cm 3 density g/cm 3

10. Converting Units: 1 cm = 10 mm 1 cm 3 = 10 1x3 mm 3 = 10 3 mm 3 1 cm 2 = mm 2 10 1x2 = 10 2 mm 2 1 m = 10 3 mm 1 m 3 = mm 3 10 3x3 = 10 9 mm 3 (1 000 mm 3 ) (100 mm 2 ) (1 000 000 000 mm 3 )

11. Arithmetic with units: In addition or subtraction the units should be the same: 2 kg + 3 kg = 5 kg 412 m - 12 m = 400 m 3.001 kg + 112 g = 3.001 kg + 0.112 kg= 3.113 kg 4.314 Gm - 0.002 Gm4.314 Gm - 2 Mm = = 4.312 Gm

12. Arithmetic with units: In multiplication or division: the units must be multiplied or divided too: 3 m × 3 m = Then, units may cancel: 5 g / 10 g = 9 m 2 98 kg m/s 2 10 kg x 9.8 m/s 2 = 0.5 (no units) 10.00 m/s x 39.37 in/m = 393.7 in/s

13. Temperature in SI units: K = o C + 273 o C = K - 273 Temperature in Fahrenheit: F = 1.8 x o C + 32 o C =

14. Temperature in SI units: The difference in the two Scales (Celsius, °C & Kelvin, K) is their zero point: - The zero point in Celsius is the freezing point of water. - The zero point on the Kelvin scale is absolute zero. 0 0 K = - 273°C. (Absolute zero (zero K) is the coldest temperature theoretically possible). You can convert between Kelvin and Celsius by using either of the following equations: K = o C + 273 o C = K - 273