Chapter 1

Metric UnitsPS 12:1PS 12:2

If I tell you that I have 11, what do you know? For a measurement to make sense, it requires

both a # and a unit. EX: I have 11 brothers/sisters. You should always express measurements in # ’s and a unit so that their meaning is clear.Many units that you are familiar with are not units

used in science( feet, inches, Fahrenheit)

SI Units of Measurement

SI Continued

Scientists use a set of measuring units called SI, or the International System of Units

This is a revised version of the metric system. By everyone using the SAME system of units,

scientists can easily interpret one another’s measurements.

7 Base Units

The seven are listed on page 16 Length – meter (m) Mass – gram (g) Volume – Cubic meter (m3) = Liter(L) Length: straight-line distance between 2 points Mass: quantity of matter in an object/sample Volume: amount of space taken up by an object

Density = Mass = Kg Volume m3

Now let’s practice a little with converting within SIkids hate dances because dj’s cruddy musick,h,da,base,d,c,mKilo., hecta, deca., base, deci., cent., milli.

Density – kg/m3

Density: the ratio of an object’s mass to its volume

EX: 5kg = _____ g 5.0kg = ______g Move the decimal 3 spaces to the right to

get to the base unit gram K,ha,da,base(gram is the base unit) Answer: 5kg = 5000g Use this ex and complete the worksheet

Worksheet practice

Metric Conversions Ladder Method

T. Trimpe 2008 http://sciencespot.net/

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

Write the correct abbreviation for each metric unit.

1) Kilogram _____ 4) Milliliter _____ 7) Kilometer _____

2) Meter _____ 5) Millimeter _____ 8) Centimeter _____

3) Gram _____ 6) Liter _____ 9) Milligram _____

Try these conversions, using the ladder method.

10) 2000 mg = _______ g 15) 5 L = _______ mL 20) 16 cm = _______ mm

11) 104 km = _______ m 16) 198 g = _______ kg 21) 2500 m = _______ km

12) 480 cm = _____ m 17) 75 mL = _____ L 22) 65 g = _____ mg

13) 5.6 kg = _____ g 18) 50 cm = _____ m 23) 6.3 cm = _____ mm

14) 8 mm = _____ cm 19) 5.6 m = _____ cm 24) 120 mg = _____ g

Metric Conversion Challenge

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

-indicates how many times a unit should be multiplied or divided by ten

Figure 15 on page 17 shows some common metric prefixes

EX 9ms = 9 s = 0.009s 1000*Note – dividing by 1000 same as multiplying

by 0.001

Metric Prefixes

http://www.metricamerica.com/mediasays.htmhttp://www.homeschoolmath.net/worksheets/measuring.php

-can make a unit larger EX 12 km = 12 x 1,000m = 12,000 m Conversion Factors – a ratio of equivalent

measurements that is used to convert a quantity expressed in one unit to another unit.

Let’s look together on page 18 of you textto work through an example of thisFACTOR LABEL Method

More on metric prefixes

Thermometer – thermo(heat)meter(measure)

An instrument that measures temperature, or how hot an object is.

Let’s look at page 21 togetherFahrenheit and Celsius and kelvin conversionsCopy the formulas found on page 20 into your

notes

Measuring Temperature

K = 0C + 273 formula Convert205 K = ______ 0C205k – 273 = -68 0C

42 0C = ___ K42 0C + 273 = 315K

Practice converting temp.

0C = (F – 32) x 5/9 AND F = 0C x 9/5 + 32 Copy the example from the bottom of Page

878 in your text into your notes Do the following conversions on your own for

practice using the example you just copied 33.182F = _____0C 14F = _____0C

More practice

65C = _____F 22C = _____F

One more set of practice in F

Length Temperature Mass Volume Time Electric Current

Second (s) Ampere (a) Kelvin (k) Meter (m) Liter (l) Kilogram (kg)

What unit to use when?

Presenting Sci. Data

Organizing Data – Scientists organize data using tables and graphs.These make it easier to spot patterns/trendsto support of disprove their hypothesisData Tables- the simplest way to organize data

Organizing data

Line Graphs – Useful for showing changes that occur in related variables

Manipulated variable – x-axis Responding variable – y-axis Slope = Rise Run

Direct proportion –As one goes up/down the other goes up/down the same amount

Inverse proportion – As one goes up/down the other goes down/up

Thumb demonstrationLook at fig. 22Do Data Analysis page 24

More organizing data

Bar Graphs- often used to compare a set of measurements, amounts, or changes.

Circle Graphs- a divided circle that shows how the part or share of something relates to the whole.