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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.