1. Using the Metric System
A. Why do scientists use the metric system?
The metric system was developed in France in used in all scientific work because it has been recognized as the world wide system of measurement since 1960.
SI system is from the French for Le Systeme International d’Unites.
The metric system is used in all scientific work because it is easy to use. The metric system is based upon multiples of ten. Conversions are made by simply moving the decimal point.

2. What is the basic unit of length?
The meter – a little longer than a yard

3. A millimeter – There are 1,000 millimeters in a meter
What do scientists use to measure the length of an object smaller than a yard?
A centimeter – one hundredth of a meter, so there are 100 centimeters in a meter
A millimeter – There are 1,000 millimeters in a meter

4. How do scientists measure long distances?
The kilometer – There are 1,000 meters in a kilometer

5. Which measurement to USE?

6. Base Units (Fundamental Units)
QUANTITY NAME SYMBOL _______________________________________________ Length meter m Mass gram g Time second s Temperature Kelvin k Volume(liquid)__________liter_____________L________________

7. SI Prefixes Prefix Symbol Multiplication Factor Term
Micro u ( ) one millionth
Milli m (0.001) one thousandth
Centi c (0.01) one hundredth
Deci d (0.1) one tenth
One Unit one
Deka dk ten
Hecto h one hundred
Kilo k one thousand
Mega M one million

8. Metric Units Used In This Class
QUANTITY NAME SYMBOL
Length meter m
centimeter cm
millimeter mm
kilometer km
Mass gram g
kilogram kg
centigram cg
milligram mg
Volume liter (liquid) L (l)
milliliter (liquid) mL (ml)
cubic centimeter (solid) cm3

9. Derived Units Base Units – independent of other units-measure
Derived Units – combination of base units-calculated
Examples
density  g/L mass / volume (grams per liter)
volume  m x m x m = meters cubed
Velocity  m/s (meters per second

10. SCIENTIFIC NOTATION
Scientific Notation: Easy way to express very large or small numbers
A.0 x 10x
A – number with one non-zero digit before decimal
x -exponent- whole number that expresses the number decimal places
if x is (-) then it is a smaller -left
if x is (+) than it is larger-right

11. PRACTICE Convert to Normal Convert to SN 2.3 x 1023 m 3,400,000,
3.4 x cm

12. Multiplying Calculating in Scientific notation
Multiple the numbers
Add the exponents
(2.0 x 104) (4.0 x 103) = 8.0 x 107

13. Dividing 9.0 x 107 3.0 x 102 3.0 x 105 divide the numbers
subtract the denominator exponent from the numerator exponent
9.0 x x 102
3.0 x 105

14. Add
Add or subtract
get the exponents of all # to be the same
calculate as stated
make sure the final answer is in correct scientific notation form
7.0 x x =
7. 0 x x = 7.3 x 104
70, ,000 = = 7.3 x104

15. subtract
7.0 x x =
7.0x 104 – .30 x 104 = 6.7 x 104
70, =67,000

16. PRACTICE Add: 2.3 x 103 cm + 3.4 x 105 cm Subtract:
Multiply:
: x 103 cm X x cm
Divide:
: x 103 cm / x cm

17. Making Unit Conversions
Make conversions by moving the decimal point to the left or the right using:
“ king henry died unit drinking chocolate milk”
Examples
10.0 cm = __________m
34.5 mL = __________L
28.7 mg = __________kg

18. Factor label method / Dimensional analysis
Use equalities to problem solve converting units.
quantity desired =
quantity given x conversion factor (equality)
A-given unit
B-desired unit
C-given unit
 A x B
C B
C must equal 1 use equality sheet

19. Equalities You Need To Know
1 km = 1000 m 1 m = 100 cm 1 m = 1000 mm 1L = 1000 mL 1kg = 1000g 1 g = 100cg 1 g = 1000 mg

20. ENGLISH TO METRIC 1 inch=2.5 centimeters 1 gal=3.8 liters
1lb= 4.4 Newtons
1qt = .94 Liters
1 ft = .30 meters
12 in = .30 meters
1 mi = 1.6 Km

21. Four-step approach When using the Factor-Label Method
it is helpful to follow a four-step approach
in solving problems:
1.What is question – How many sec in 56 min
2. What are the equalities- 1 min = 60 sec
3. Set up problem (bridges) 56 min sec
1 min
4. Solve the math problem -multiple everything on top
and bottom then divide 56 x 60 / 1