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)

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.

Giga (G) Mega (M) Kilo (k) Hecto (h) Deca (da) BASE UNIT (m,L,g,etc) Deci (d) Centi (c) Milli (m) Micro (μ) Nano (n) Pico (p)

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 2 ). or 3 kL x = 3 x 10 2 daL Multiply when converting from larger to smaller units. ( 300 daL)

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 (-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

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 (-9) = = 10 8 ). or 25 ng x = 25 x dg Divide when converting from smaller to larger units. = 2.5 x dg

Giga (G) Mega (M) Kilo (K) Hecto (h) Deca (da) BASE UNIT Deci (d) Centi (c) Milli (m) Micro (μ) Nano (n) Pico (p) Multiply Divide Shift the decimal point to the right Shift the decimal point to the left

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

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

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

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 kg g = kg kg= kg Gm Gm4.314 Gm - 2 Mm = = Gm

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) m/s x in/m = in/s

Temperature in SI units: K = o C o C = K Temperature in Fahrenheit: F = 1.8 x o C + 32 o C =

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 o C = K - 273