Measurements in Science
All measurements and calculations must
use the METRIC SYSTEM!
4 primary measurements in science:
1) length- distance from one point to another; basic unit
of measurement is the meter (m).
2) mass- amount of matter in an object; basic unit of
measurement is the kilogram (kg).
3) volume- amount of space an object takes up; basic unit
of measurement is the liter (L).
4) density- amount of mass in a given amount of space;
basic unit of measurement is the g/cm3 or g/mL
Metric Conversions
Ladder Method
T. Trimpe 2008 http://sciencespot.net/
Ladder Method
1
2
KILO
1000
Units
3
HECTO
100
Units
DEKA
10
Units
DECI
0.1
Unit
Meters
Liters
Grams
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.
CENTI
0.01
Unit
MILLI
0.001
Unit
4 km = _________ m
Starting Point
Ending Point
How many jumps does it take?
4. __. __. __. = 4000 m
1
2
3
Conversion Practice
Try these conversions using the ladder method.
1 g
1000 mg = _______
1000 mL
1 L = _______
1600 mm
160 cm = _______
14000 m
14 km = _______
.109 kg
109 g = _______
.25 km
250 m = _______
Compare using <, >, or =.
56 cm
6m
7g
698 mg
Metric Conversion Challenge
Write the correct abbreviation for each metric unit.
kg
1) Kilogram _____
4) Milliliter _____
mL
7) Kilometer _____
km
m
2) Meter _____
mm
5) Millimeter _____
cm
8) Centimeter _____
g
3) Gram _____
L
6) Liter _____
mg
9) Milligram _____
Try these conversions, using the ladder method.
10) 2000 mg = _______
g
2
15) 5 L = _______
5000 mL
20) 16 cm = _______
mm
160
11) 104 km = _______
104000 m
16) 198 g = _______
.198 kg
21) 2500 m = _______
km
2.5
4.8 m
12) 480 cm = _____
.075 L
17) 75 mL = _____
22) 65 g = 65000
_____ mg
13) 5.6 kg = 5600
_____ g
.5
18) 50 cm = _____
m
63 mm
23) 6.3 cm = _____
14) 8 mm = _____
cm
.8
19) 5.6 m = _____
560 cm
24) 120 mg = _____
.12 g
Compare using <, >, or =.
25) 63 cm
26) 536 cm
6m
53.6 dm
27) 5 g
28) 43 mg
508 mg
5g
29) 1,500 mL
30) 3.6 m
1.5 L
36 cm
Lesson 1:
Length
T. Trimpe 2008 http://sciencespot.net/
English vs. Metric Units
Which is longer?
A. 1 mile or 1 kilometer
B. 1 yard or 1 meter
1 mile
1.6 kilometers
C. 1 inch or 1 centimeter
1 inch = 2.54 centimeters
1 yard = 0.9444 meters
Left Image: http://webapps.lsa.umich.edu/physics/demolab/controls/imagedemosm.aspx?picid=1167
Right Image: http://share.lancealan.com/N800%20ruler.jpg
Metric Units
The basic unit of length in the metric system in the meter and is represented by a
lowercase m.
Standard: The distance traveled by light in absolute vacuum in 1⁄299,792,458 of
a second.
Metric Units
1 Kilometer (km) = 1000 meters
1 Meter = 100 Centimeters (cm)
Click the image to
watch a short video
about the meter.
1 Meter = 1000 Millimeters (mm)
Which is larger?
A. 1 meter or 105 centimeters
C. 12 centimeters or 102 millimeters
B. 4 kilometers or 4400 meters
D. 1200 millimeters or 1 meter
Measuring Length
How many millimeters are in 1 centimeter?
1 centimeter = 10 millimeters
2.8
What is the length of the line in centimeters? _______cm
28
What is the length of the line in millimeters? _______mm
3
What is the length of the line to the nearest centimeter? ________cm
HINT: Round to the nearest centimeter – no decimals.
Ruler: http://www.k12math.com/math-concepts/measurement/ruler-cm.jpg
Lesson 2:
Mass
T. Trimpe 2008 http://sciencespot.net/
English vs. Metric Units
Which is larger?
1. 1 Pound or 100 Grams
1 pound = 453.6 grams
2. 1 Kilogram or 1 Pound
3. 1 Ounce or 1000 Milligrams
1 ounce of gold =
28,349.5 milligrams
100 kilogram =
220 pounds
Metric Units
Mass refers to the amount of matter in an object.
The base unit of mass in the metric system in the kilogram
and is represented by kg.
Standard: 1 kilogram is equal to the mass of the International
Prototype Kilogram (IPK), a platinum-iridium cylinder kept
by the BIPM at Sèvres, France.
Metric Units
1 Kilogram (km) = 1000 Grams (g)
Kilogram Prototype
Click the image to
watch a short video
about mass.
1 Gram (g) = 1000 Milligrams (mg)
Which is larger?
A. 1 kilogram or 1500 grams
C. 12 milligrams or 12 kilograms
B. 1200 milligrams or 1 gram
D. 4 kilograms or 4500 grams
Kilogram Prototype Image - http://en.wikipedia.org/wiki/Kilogram
Measuring Mass
We will be using triple-beam balances
to find the mass of various objects.
The objects are placed on the scale and
then you move the weights on the beams
until you get the lines on the right-side of
the scale to match up.
Once you have balanced the scale, you add up
the amounts on each beam to find the total mass.
What would be the mass of the object measured
in the picture?
70 g + _______
300 g + ______
3.4 g = ________
373.4 g
_______
Top Image: http://www.southwestscales.com/Ohaus_Triple_Beam_750-SO.jpg
Bottom Image: http://www.regentsprep.org/Regents/biology/units/laboratory/graphics/triplebeambalance.jpg
Measuring Mass – Triple-Beam Balance
1st – Place the film canister on the scale.
2nd – Slide the large weight to the right until the arm drops below the
line. Move the rider back one groove. Make sure it “locks” into place.
3rd – Repeat this process with the top weight. When
the arm moves below the line, back it up one groove.
4th – Slide the small
weight on the front
beam until the lines
match up.
5th – Add the amounts on each beam to find the total mass to the nearest tenth of a
gram.
Click here to try an online activity.
Lesson 3:
Volume
T. Trimpe 2008 http://sciencespot.net/
English vs. Metric Units
Which is larger?
1 fl oz = 29.573 ml
A. 1 liter or 1 gallon
1 12-oz can of soda
would equal
approximately 355 ml.
B. 1 liter or 1 quart
C. 1 milliliter or 1 fluid ounce
1 quart = 0.946 liters
1 gallon = 3.79 liters
It would take approximately 3 ¾
1-liter bottles to equal a gallon.
Metric Units
Volume is the amount of space an object takes
up.
The base unit of volume in the metric system in
the liter and is represented by L or l.
Standard: 1 liter is equal to one cubic decimeter
Metric Units
1 liter (L) = 1000 milliliters (mL)
1 milliliter (mL) = 1 cm3 (or cc) = 1 gram*
Which is larger?
A. 1 liter or 1500 milliliters
Click the image to
watch a short video
about volume.
B. 200 milliliters or 1.2 liters
C. 12 cm3 or 1.2 milliliters*
* When referring to water
Liter Image: http://www.dmturner.org/Teacher/Pictures/liter.gif
Measuring Volume
We will be using graduated cylinders to
find the volume of liquids and other objects.
Read the measurement based on the bottom of the
meniscus or curve. When using a real cylinder, make
sure you are eye-level with the level of the water.
43
What is the volume of water in the cylinder? _____mL
What causes the meniscus?
A concave meniscus occurs when the molecules of the liquid
attract those of the container. The glass attracts the water on
the sides.
Top Image: http://www.tea.state.tx.us/student.assessment/resources/online/2006/grade8/science/images/20graphicaa.gif
Bottom Image: http://morrisonlabs.com/meniscus.htm
What is the volume of water in each cylinder?
Pay attention to the scales for each cylinder.
Images created at http://www.standards.dfes.gov.uk/primaryframework/downloads/SWF/measuring_cylinder.swf
Measuring Liquid Volume
Measuring Solid Volume
9 cm
8 cm
We can measure the volume of regular object
using the formula length x width x height.
10
_____
cm X _____
8 cm X _____
9 cm = _____
720 cm3
We can measure the volume of
irregular object using water displacement.
260mL
Amount of H2O with object = ________
200mL
About of H2O without object = ________
60mL
Difference = Volume = ________
Click here for an online activity about volume.
Choose Lessons  Volume & Displacement
http://resources.edb.gov.hk/~s1sci/R_S1Science/sp/e
n/syllabus/unit14/new/testingmain1.htm
10 cm
Measuring Density
Density is a measure of how much matter is in a given volume.
Density = mass/volume
m
D = ------V
Calculate the mass of the object using a balance.
Calculate the volume of the object using either a
mathematical formula or water displacement.
Divide the mass by the volume.
Label with the appropriate units:
g/cm3 or g/mL
Graphing in Science
Most Common Types of Graphs:
Bar
Circle
Line
Graphs are a visual representation of data that
reveals patterns or trends not easily seen by numbers.
Accuracy vs. Precision
accuracy- how close a measurement is to a true or
accepted value.
precision- how close a group of measurements are to
each other.
The key is to be accurate and precise!!
Percent Error
percent error- determines the accuracy of an experimental
measurement to the accepted value.
E% =
difference between exp. value and true value X 100
true value
measured as a percent (%)
Creating a Graph
1. Create axes.
Number of Reindeer Needed to Deliver
Presents the Santa Roos’s Students
x-axis = horizontal axis
y-axis = vertical axis
3
2. Label axes.
horizontal axis = dependent variable
vertical axis = independent variable
3. Create the scales.
Number of 2
Reindeer
needs to cover all data
4. Plot data.
5. Draw line of best fit or make bars.
shows general pattern in data
6. Title the graph
relates independent to dependent variables
1
0
15
3
45
0 of
Number
Students
Useful Graph Information
linear graph- graph whose data creates a straight line.
graph whose data does not create a
nonlinear graph- straight line.
slope - a line that indicates how a change in the
independent variable effects the
dependent variable.
origin - where x & y axes meet.
coordinate - pair of numbers that indicate a position on
a graph.