1. Measurement
in Science

2. Why are measurement standards important?
What is a standard?
It is an exact quantity that people agree to use for comparison.
Why are measurement standards important?
A meter in the U.S. is the same as a meter in France.

3. International Standards
SI Units are...
International Standards
Abbreviated SI from the French Le Systeme Internationale d’Unites

4. International Standard Units (SI)
If you do not have Internet access, skip the next three slides and use the flashcards (provided by your teacher) to make chart above. Practice putting the flashcards together without using the chart. When you can make the chart without looking at the answers, put a “” the blanks for the next three slides on your handout.

5. SI Units for Measurement Used in Science
Length
Metric ruler:
Measured in meters (m)
Volume
Graduated cylinder:
Measured in milliliters (mL)
Mass
Balance:
Measured in grams (g)
Temperature
Thermometer:
Measured in degrees Celsius (OC)

6. Putting It All Together
prefix
symbol
unit
centi- c m
meter
(0.01)
hundredth of a meter
milli- L m
liter
(.001)
thousandth of a liter
kilo- k g
gram
(1000)
thousand grams

7. What is the length of the red line? 6.2 cm or 1.2 cm
Using a Ruler
When measuring an object with a ruler, never start with at the “0” mark.
Rulers are less accurate due to wear and tear at the ends.
Begin at the 2, 4, 5 or 6 cm mark in order to get the most accurate mark. 5 6
What is the length of the red line? 6.2 cm or 1.2 cm
The red line would be 1.2 cm because the “5” is the starting point.
6.2 – 5 cm = 1.2 cm

8. Reading the Meniscus
When measuring liquid volume in a graduated cylinder, a meniscus often forms where the liquid ends.
graduated cylinders
In order to read this liquid volume, you must be at “eye-level” to the level of the liquid.
You take the reading at the BOTTOM of the meniscus.
The liquid level is 36.5 mL.

9. Read these liquid volumes in mL:B.

10. Use your safety guide to help you identify problems.
Do the safety scenario on your handout.
Use your safety guide to help you identify problems.