Units of Measurement

SI – Le Systeme International d’Unites

AKA: the Metrics System

SI Base Units

Adopted: 1960

Standard international measurement

Powers of Ten

Mass vs. Weight

Mass measures the quantity of matter

Standard unit = g (gram)

Instrument = Balance

Weight measures the gravitational pull on matter

Standard unit = N Newton is force

Instrument = Spring Scale

Length

Distance measurement

Standard unit = m (meter)

Instrument = Ruler

Volume

Amount of space occupied by an object For non-liquid volumes, standard unit = m3

For liquid volumes, standard unit = L (liter)1 mL = 1 cm3

Instrument = graduated cylinders or ruler

Temperature

Standard unit = Celsius

Using Celsius, water freezes at 0 degrees, and boils at 100 degrees

F = 9/5C + 32

C = 5/9 (F – 32)

Conversions and ScaleLarger ----------------------Smaller

(k) kilo

(h) hecto

(da) deca

(d) deci

(c) centi

(m) milli

Length km hm dam m dm cm mm

Mass kg hg dag g dg cg mg

Liquid Volume

kL hL daL L dL cL mL

KILO1000Units

HECTO100

Units

DEKA10

UnitsDECI

0.1Unit

CENTI0.01Unit

MILLI0.001Unit

MetersLitersGrams

Ladder Method

How do you use the “ladder” method?

1st – Determine your starting point.

2nd – Count the “jumps” to your ending point.

3rd – Move the decimal the same number of jumps in the same direction.

4 km = _________ m

12

3

How many jumps does it take?

Starting Point Ending Point

4.1

__.2

__.3

__. = 4000 m

Try these conversions using the ladder method.

1000 mg = _______ g 1 L = _______ mL 160 cm = _______ mm

14 km = _______ m 109 g = _______ kg 250 m = _______ km

Conversion Practice

Compare using <, >, or =.

56 cm 6 m 7 g 698 mg

Compare using <, >, or =.

25) 63 cm 6 m 27) 5 g 508 mg 29) 1,500 mL 1.5 L

26) 536 cm 53.6 dm 28) 43 mg 5 g 30) 3.6 m 36 cm