1. Daily Science (August 27th)
How many sig figs are in ?
Round to two sig figs
Write in scientific notation
Pull out your sig figs worksheet to check over

2. Metric Units
pg. 13

3. SI Units
SI units-a standard set of units scientists use to measure quantities
Allows for consistency around the world
Sig figs- conversions used in dimensional analysis and metric conversions have an infinite amount of sig figs and are not included when determining sig figs

4. SI Base Units Length Meter m Mass Gram g Volume Liter L Time Second s
Measurement
SI Base Unit
Symbol of units
Length
Meter m
Mass
Gram g
Volume
Liter L
Time
Second s
Temperature
Kelvin K
Amount of substance
Mole
mol
Energy
Joule J

5. SI Prefixes ***Write the prefix 1st then the base unit ***
Factor
Name
Symbol
106
mega M
103
kilo k
101
Deca Da
Base Unit
m, L, sec, g
10-1
deci d
10-2
centi c
10-3
milli m
10-6
micro
10-9
nano n

6. Using the Number Line to Convert Btw. Prefixes

7. Dimensional Analysis
A way to convert from one prefix or unit to another prefix or unit.
Multiplying fractions

8. Steps for dimensional analysis
1. Start with what you are given (add a x and a fraction )
2. Place the given unit on the bottom of your ‘fraction’ so it will cancel out Then place the desired unit on top.
3. Place a 1 in front of the larger unit
Place the value for the smaller unit in the empty space
Use known relationships (i.e.12 in =1 ft)
4. multiply numbers on the top and divide numbers on the bottom of fraction
Ex. how many cm in 1.5 m?
1.5 m x = cm
100 1 cm
150 m

9. Check yourself Smaller unit to bigger unit=smaller number
bigger unit to smaller unit= bigger number

10. Example How many cm are in 1.3 Km? How many dL are in 3.4 mL?
Convert 2.00 mile into inches.
1 mile=5,280 feet
I am 883,008,000 seconds old. How old am I in years?