Metric PrefixesLook along on your

Conversion Factor sheet

Metric System Review

Metric PrefixMetric Prefix – symbol that goes in

front of a base unit that indicates a portion of that unit

Example:kilo + meter = kilometer = 1,000 meters

1 km = 1,000 m

Common Base Units: meters (m), grams (g), Liters (L), seconds (s)

1 Megameter = 1Mm

Mega = M

1 Mm = 1,000,000 m = 106 m

1 Megameter = From here to Oklahoma

1 kilometer = 1km

kilo = k

1 km = 1,000 m = 103 m

2.5 laps = 1 kilometer

1 centimeter = 1cm

centi = c

1 m = 100 cm = 102 cm

The width of your thumb = 1 cm

1 millimeter = 1 mm

milli = m

1 m = 1000 mm = 103 mm

The width of a quarter = 1 mm

1 micrometer = 1 μm

micro = μ

1 m = 1,000,000 μm = 106 μm

The width of a hair = 1 μm

Example 1)How many centimeters (cm) are in 1 meter (m)?

Prefix: centi-Base unit: meters

m m

1m = 100cm

Example 2)How many milligrams (mg) are in 1 gram (g)?

Prefix: milli-Base unit: gram

g g

1g = 1000mg

Quick Check 1What is the relationship between Liters (L) and

kiloLiters (kL)?Prefix: kilo-Base unit: Liter

L L

1000L = 1kL

Quick Check 2How many nanosecond (ns) are in 1 second (s)?

Prefix: nano-Base unit: second

s s

1s = 109 ns

Conversion Factors

Why do we need conversions?

Line is 2.75 inches longWe need to know the length in cm

Part 1: Writing Conversion Factors as Ratios

ExampleFor each conversion

factor, there are

ratios possible.

1 in = 2.54 cm

2

Part 1: Writing Conversions as RatiosLet’s Practice: 1,000 mg = 1 g

What are my possible ratios?

Part 2: Writing Ratios from a ProblemStep Example

1) Find your known (this is the unit you want to convert) and your unknown.

2.75 in = ________ cm

Known: in

Unknown: cm

Part 2: Writing Ratios from a ProblemStep Example

2) Find the conversion factor that includes both known and unknown units.

2.75 in = ________ cm

Known: in

Unknown: cm

Relationship: 2.54cm = 1in

Part 2: Writing Ratios from a ProblemStep Example

3) Write this conversion factor as a ratio.

2.75 in = ________ cm

Relationship: 2.54cm = 1in

Part 2: Writing Ratios from a ProblemLet’s Practice: Step 1

6,280 m = _____________ km

Known: m

Unknown: km

Part 2: Writing Ratios from a ProblemLet’s Practice: Step 2

6,280 m = _____________ km

1,000 m = 1 km

Part 2: Writing Ratios from a ProblemLet’s Practice: Step 3

6,280 m = _____________ km

1,000 m = 1 km

Conversion Problems

Solving Conversion ProblemsStep Example 1

1) Set up the equation. The known goes in the upper left corner.

2.75 in = ________ cm

2.75 in

Solving Conversion ProblemsStep Example 1

2) On the right side, put the conversion factor that will cancel.

2.75 in = ________ cm

2.75 in

Solving Conversion ProblemsStep Example 1

3) Multiply across the top, then divide.

2.75 in = ________ cm

2.75 in= 6.985 cm

Solving Conversion ProblemsExample 2)

6,280 m = _____________ km

6,280 m

Solving Conversion ProblemsExample 2)

6,280 m = _____________ km

6,280 m

Solving Conversion ProblemsExample 2)

6,280 m = _____________ km

6,280 m= 6.28 km