1. Warm up 9/13 There are two focusing knobs on a microscope:
What are they?
Define when to use each.
How do you find the total magnification of the microscope.
What does the diaphragm do on a Microscope?

2. Exam Friday Study guide: Due Friday Characteristics of Life
Microscopes
Scientific Method/ Experimental Design
Metric Conversion

3. Exam Friday Griffin Virtual Lab With Mr. Lee
Tonight at 6 pm there is a link on Mr. Lee’s website.
To sign up for reminders for future GVL text @biogvl to or add to Remind app

4. How Do Scientists Measure?
The Metric System
AKA SI or Système International
How Do Scientists Measure?

5. Way Back When . . .
When people first started to measure things, the systems were different in different parts of the world.
Many systems were based on parts of the body.
Foot Inch

6. How to Measure? Many countries tried to make a system of measurement.
Both France and England came up with systems that are used today.
England started the English Standard System and France started the Metric System.

7. Comparing the two Systems . . .
English Standard System
Based on:
2, 3, 4, 8, 16
Generally uses fractions
2 pints in a quart
3 feet in a yard
4 quarts in a gallon
12 inches in a foot
16 ounces in a pound
Metric System
Based on: 10 (like U.S. money)
Generally uses decimals
100 centimeters in a meter
1000 grams in a kilogram
1000 milliliters in a liter

8. Why the Metric System? Over 95% of the world uses the Metric System.
The metric or SI (system international) system is aids scientists in sharing measurements
No need to convert another person’s data if we all work in SI
Ex/ NASA still works in imperial units and has had difficulty when needing to work with other groups that use metric
In 1999 the Mars Climate Orbiter was lost because the altitude control system used imperial units and the navigation software used metric.

9. Metric
Units can be scaled by factors of 10 depending on what you are measuring
So it can be used for small stuff as well as large
king Henry Died by drinking chocolate milk
kilo- Hecto- Deca- Base- deci- centi- milli-
/10th 1/100th 1/1000th

10. How many jumps does it take?
Ladder Method 1 2 3
KILO 1000 Units
HECTO 100 Units
DECA 10 Units
DECI 0.1 Unit
Meters Liters Grams
CENTI 0.01 Unit
MILLI Unit
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
Starting Point
Ending Point
How many jumps does it take? 4. 1
__. 2
__. 3
__.
= 4000 m

11. Conversion Practice Try these conversions using the ladder method.
2000 mg = _______ g 5 L = _______ mL 16 cm = _______ mm
Compare using <, >, or =.
76 dm m 5 g mg

12. Mass Measurement: Mass Unit used: Gram (g) Tool Used: Balance
A paper clip has a mass of about 1 gram.

13. Warm up 9/14
What are the metric prefixes which we remember with king Henry Died by drinking Chocolate Milk
What percentage of the world’s countries use metric?
When is the first Exam?
When is the Study Guide Due?

14. A centimeter is about the width of a small fingernail
Length/Distance
Measurement: length/distance
Unit used: Meter (m)
Tool Used: Ruler/meter stick
A centimeter is about the width of a small fingernail

15. A liter is just a little bit more than 1 quart (or 2 pints)
Volume
Measurement: Volume
Unit used: Liter (l)
Tool Used: graduated cylinder
A liter is just a little bit more than 1 quart (or 2 pints)

16. Reading a Gradated Cylinder
Measure from the bottom of the meniscus
66 ml

17. Temperature Measurement: Temperature Unit used: Celsius (C)
Tool Used: Thermometer
0o Celsius= freezing
100o Celsius= boiling

18. Today . . .
As of the late 1970s, only the United States, Liberia (Africa) and Myanmar (formerly Burma in Asia) use the English Standard System.
Every other country, and scientists worldwide, use the metric system.

19. Practice Problems Convert 15 grams (g) to kilograms (kg)
15 g X 1 kg = kg
1000 g
.015

20. Classwork Homework Metric System Pre-Lab Study Guide
Due Tomorrow (Thursday)
Study Guide
Due Tuesday Sept 22
Exam Thursday Sept 24