Measuring Basics
• Volume – amount of space occupied by
an object
• Length – distance between two points
• Mass – amount of matter in an object
• Time – period between two events
• Temperature – measure of the energy
particles have
Measuring … … using
Significant Figures!!
• Significant figures is used to show the
accuracy in a measurement:
Accuracy depends on the smallest increment
shown on measuring tool (meter stick,
balance, etc.)
The last decimal place (digit) is an estimate
The more decimals places (digits), the more
accurate that measurement is
Measuring
• 4 sided meter stick example
The 3 steps to measuring with significant
figures
Think about a number
642.351
Hundreds, Tens, Ones, Tenths, Hundredths, Thousandths
1. Determine the smallest increment
on the measuring tool
What decimal place does
each small line represent?
1.
2.
3.
4.
5.
6.
Hundreds
Tens
Ones
Tenths
Hundredths
thousands
2. Determine the next decimal place
beyond that smallest increment
(Your measurement will be recorded to this decimal place)
What is the next decimal
place?
1.
2.
3.
4.
5.
6.
Hundreds
Tens
Ones
Tenths
Hundredths
thousands
3. Record the measurement, estimating
one decimal place past the smallest
increment shown
What is the proper
measurement?
1.
2.
3.
4.
5.
6.
824 cm
82.4 cm
8.24 cm
8.240 cm
82 cm
8.2 cm
The proper measurement:
The Pencil is
more than 8.2
cm long …
… But less
than 8.3 cm
long
… so we estimate to the
next decimal place.
8.24cm
The decimal places
recorded shows accuracy of
the measurement tool
The measurement recorded
is to the hundredths place,
so we know the smallest
increment was to the tenths
Volume
Graduated
Cylinder
You always
estimate one
decimal
place PAST
the smallest
increment
shown
?
Measuring Volume
7
Meniscus –
read
measurements
at bottom of
meniscus
Volume?
1.
2.
3.
4.
5.
50.2 mL
50.28 mL
52.8 mL
52.80 mL
I have no idea
Length
Meter stick
or
Ruler
Length?
1.
2.
3.
4.
8 mm
8.0 mm
8.00 mm
80 mm
Now for the balance!!!
Mass?
1.
2.
3.
4.
5.
6.
602005.72
200605.72
260.572
265.72
265.720
265.7
Temperature
Fahrenheit (º F ), Celsius (º C ), Kelvin (K)
º C = 5 (º F - 32.0 º)
9
º F = 9 (º C) + 32.0 º
5
K = º C + 273
If you need extra help!
Basic measuring practice
Measurement
Task
Volume
Volume of water in small
graduated cylinder
Answer (units)
mL
More Volume
Volume of water in large
graduated cylinder
mL
Mass
Mass of pen
g
Length
Length of pen
cm
Temperature
Temperature of water in
graduated cylinder
ºC
Images Cited
•
•
•
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www2.oregonscientific.com
http://www.labrecyclers.com/pics/ohaus_trip.jpg
http://www.bourne.k12.ma.us/Class%20Links/Smith/Smith/images/tripple%20beam%20balance.jpg
http://www.northernbrewer.com/pics/fullsize/lab-thermometer.jpg