04- Metric system.pptx

Objective

You will be able to:

Identify common units in the

metric system

Convert with in the metric system

by moving the decimal place

The Metric

System

“I’m ten times

better than the

Standard system of

measurement!”

Multiply each of the

following numbers by 10

15 x 10 =

235 x 10 =

12.4 x 10 =

150

2350

124

Multiply each of the

following numbers by 100

23 x 100 =

172 x 100 =

32.3 x 100 =

2300

17200

3230

Multiply each of the

following numbers by 10

15 x 1/10 =

235 x 1/10 =

12.4 x 1/10 =

1.5

23.5

1.24

Multiply each of the following #

by 1/100 (divide by 100)

23 x 1/100 =

172 x 1/100 =

32.3 x 1/100 =

0.23

1.72

Nice!

If you can multiply & divide by

10 (or any power of 10), then

the metric system will be easy

for you.

The Metric System

 Almost all other countries and ALL

scientists use it

Coordination of data, consistency

Space Probe Crash

Also called the SI system

(International System of Units) It is a base ten system

The Metric System

Metric (SI) Unit Standard System Meter (m)

(mm,cm,km)

Length Yard

(inch, foot, mile)

Gram (g)

(mg, cg, kg)

Mass Pound (ounce, ton) Celsuis (◦C) Temperature Fahrenheit (◦F) Liter (L)

(mL, cL, kL)

Volume Quart

(tspn, tbl, cup, pint, gallon)

Second (s) Time Second (s)

Speed (m/s) Derived Units

(Combination of Base Units)

The Metric System

Prefix

Symbo

l

Value

Factor

kilo- k 1 000

(thousand) 10

3

hecto- h 100 (hundred) 102

deca- da 10 (ten) 101

m, L, s, g One (Base

Unit) 10

0

deci- d 0.1 (tenth) 10-1

centi- c 0.01

(hundredth) 10

-2

milli- m 0.001

(thousandth) 10

The Metric System: Decimal Method

If moving from left to right (larger to

smaller), move the decimal place to the

right.

Ex. km to cm

If moving from right to left (smaller to

larger), move the decimal place to the left.

Ex. 5mL to kL

(g, m, L)

Metric system converting: Decimal places

Change: 400g to kg

The Metric System

From a smaller unit to a bigger

unit; Divide

Base units m, g, l, s

deci 10

or

0.1

centi 10

or

0.01

milli 10

or

0.001

deca 10

or 10

hecta 10

or

100

kilo 10

or 1

000

From a bigger unit to a smaller unit;

Converting in the Metric System:

Dimensional Analysis

Moving the decimal place is helpful and fast, but not as useful as using dimensional analysis and

conversion factors.

Ex. How many mm in 1m?

First – Determine what the conversion factors are, how are the two units related.

m

mm

1

1000

m

mm

:

1

1000

m

m

1000

1

Converting in the Metric System:

Dimensional Analysis

Ex. How many mm in 1m?

Second- Which conversion factor will let you

cancel out the unit you have and end with the unit you want, when multiplying?

1m x ____?______

We want mm and need to cancel out m:

m

mm

1

1000

m

mm

:

1

1000

mm

m

1000

1

Converting in the Metric System:

Dimensional Analysis

Ex. How many mm in 1m?

Third – Set up the conversion and carry it out.

1

000mm





m

mm

m

1

1000

1

Converting in the Metric System:

Dimensional Analysis

You try: How many ml are in 3dl?

First - What is the relation ship between ml and dl, and the possible conversion factors?

Second – which conversion factor will get give us our desired unit?

Third – Cary out the conversion

300ml





dl

ml

dl

1

100

3

Metric System Flow Chart









Kilo

base

deci centi milli

   

X

1000

10

10

10

Converting Metric Units

Expectation – by repeated practice, you

will be able to do these conversions in

your head.

Making more from a larger number

Multiply by base 10 (number of

spaces) and move decimal to right

Ex. Convert 2.3 kg to ______ g. Ex. Convert 5.7 g to ______ mg.

The Metric System

 Converting Metric Units



Making less from a number



Divide by base 10 (number of

spaces) and move decimal to

the left

Ex. Convert 1.5 g to ______ kg.

Ex. Convert 8.2 mg to ______ g.

Practice

How many mm are there in 2.134km?

Need to go from km to mm

km



base(meter)



deci



centi



milli

2.134km x 1 000 000mm =

km

Bell Work: Pre AP

19-Aug-2011

Little Johnny was walking home &

has to climb over a concrete box

that is as tall as him, has a

length

2.5 times his height

, &

has a

width 1.5 times

his arm

span. If little Johnny is

1650mm

tall

& has an

arm span of

1700mm

, what is the volume of

the concrete box in cm

? (hint

Bell Work: Chem 1-2

19-Aug-2011

A student read the volume

of a graduated cylinder

to be 30.5mL; however,

they needed to report

the value in dL. What is

the volume in dL?

Objectives

Use dimensional analysis to convert units in the metric system

Dimensional Analysis

Start with

the value

and unit

you have

Choose a conversion

factor that allows you to

cancel out the starting

(given) unit

Example: 4.5dm to km





given

desired

given





dm

km

dm

10000

1

5

.

4

Using Dimensional Analysis

how tall are they in cm?

First: Find an equivalence

between in and cm, then

write the two conversion

factors

Second: Pick the conversion

factor that lets you cancel out

the given unit

or

Third: Carry out

the conversion

cm

in

54

.

2

1

in

cm

1

54

.

2





in

cm

in

1

54

.

2

71

The Metric

System

Practice problems – Convert

550 millimeters to meters

3.5 moles to millimoles

1.6 kilograms to gram

2500 milligrams to

kilograms

4.0 centimeters to

millimeters

Turn in

Pre-AP

Staple the following in the order shown and turn in to your period box!

1. Basic math Skills (if you have not turned in yet) 2. Concept review p26, 1& 2

3. HW p37 # 4, 5, 6

4. HW p45 # 24, 30, 32, 35, 36* 5. Basic Lab Skills lab

Turn in

Chem 1-2

Staple the following in the order shown and turn in to your period box!

1. Basic math Skills (if you have not turned in yet) 2. Concept review p26, 1& 2

3. HW p30 # 4, 5

4. Basic Lab Skills lab 5. Bellwork #1

Before you Leave

What are the four (4) prefixes you need to commit to memory?

Write out the step for using dimensional analysis on a scratch piece of paper.

Bell Work: Pre- AP 22-Aug-2011

On a New Bellwork; #2

What is the area of the circle in the picture below in m2? (A

circle = π r2, 1ft = 0.305m)

Diameter

is 1

Bell Work: Chem 1-2 22-Aug-2011

On a New Bellwork; #2

If the top of your desk is 60cm x 44cm what is the area of the work surface in mm2? Area of

a rectangle is A =L x W

If the height of the desk is 2cm what is the volume in cm3?

Objective

Dimensional analysis questions

See the metric system at work in the length lab in partner pairs

Before you leave…

Now that you have finished

measuring with the metric

system, why do you think it

would be very difficult for the

USA to switch completely over

to the metric system even

The Metric

System

 Scientific Notation – Scientists use scientific

notation to express very large or small numbers. For instance, the span of the universe and the

The Metric

System

Rules for converting (10 345)



Move the decimal to make a number

between 1 and 10.



Write (x 10

)



Move the decimal to the right,

exponent (1.0345 x 10

)



Move the decimal to the left, -

The Metric

System

Scientific Notation – going the other

way

 The exponent is the number of places you

move the decimal



If the decimal is negative (-),

move left



If the decimal is positive (+),

Convert into Scientific Notation

10 000 0.0034

23 000 000 0.000 000 045

4 500 000 000 0.000 000 000 000 056 1.456 x 104 7.0 x 103

9.11 x 106 3.3 x 10-9