Unit ConversionObjectives:- Transform a statement of equality to a

conversion factor- Perform unit conversion problems within

the SI metric system

SI Prefix Conversion1. Find the difference between the exponents of the two

prefixes.

2. Move the decimal that many places.

SI Prefixes

Prefix Scientific notation Meaning

mega (M) 106 1 000 000

kilo (k) 103 1 000

hecto (h) 102 100

deka (da) 101 10

Base Unit 100 1

deci (d) 10-1 0.1

centi (c) 10-2 0.01

milli (m) 10-3 0.001

micro () 10-6 0.000 001

nano (n) 10-9 0.000 000 001

mo

ve le

ft

mo

ve r

igh

t

• Ex:• How many mL are in 0.032 L?

• 0.032 L = _____ mL• 0.032 L = 32 mL

• You Try!• a) 20 cm = ____ m

• 0.2 m

• b) 805 dm = ____ km• 0.0805 km

• c) 0.177 L = ____ mL• 177 mL

Conversion Factors• Conversion factor: a ratio from the equality between two

different units that can be converted from one unit to the other

• Ex: • 1 dollar = 4 quarters or 4 quarters = 1 dollar• Can be written like:• or

• You can convert factors if you know the relationship between the unit you have and the unit you want!

Dimensional Analysis• The “Factor-Label” Method

• Units are canceled (or “factored”) out

• Steps:

1. Identify starting and ending units.

2. Line up conversion factors so units cancel out.

3. Multiply all top numbers & divide by each bottom number.

4. Check units & answer.

3

3

cm

gcm g

Practice1.Convert the following metric measurements: a.23.0 g = _______ kgb.0.00817 hg = _______ gc.5.312 daL = _______ Ld.0.0093 m = _______ km

2.Convert each of the following using the factor label method:a.How many kilometers are in 3500 meters?b.How many milligrams are in 8.71 grams?c.How many liters are in 20.7 dekaliters?d.How many grams are in 40.3 centigrams?