1. Measurements in Science & Scientific Notation

2. Differences in Measurement
Qualitative Measurements – a description using words about an observation
Color, smell
Quantitative Measurements – mathematical equations, measured amounts
A = l x w
V = l x w x h

3. Advantages to Quantitative Measurements
Numbers are universal- they are known throughout the world
Languages are not- many language barriers
You can communicate with everyone with numbers

4. Accuracy vs. Precision

5. Precision
Precision - ability of a measurement to be consistently repeated.
Ex. A thermometer measures the same temperature of a liquid 5 times
Ex. A gun hits the same place on a target every time

6. Accuracy
Accuracy - ability of a measurement to match the actual value of the quantity being measured
Ex. A thermometer measures the exact temperature of a liquid
Ex. A gun hits the bull’s eye on a target

7. Roles in Science
It is important for science to strive to be both precise and accurate
We cannot be more precise or accurate than the instruments we are using
Ex. A ruler can accurately measure out to 2 decimal places
Ex inches
We could not get a reading of inches from a ruler

8. Mass vs. Weight Important to note that these are not the same thing!
Mass – the amount of matter in an object
In space, the more mass an object has, the more gravitational attraction it has
Weight – a measure of the gravitational force exerted on an object
Being on a different planet would give you a different weight
Ex. The Moon’s gravity is about one-sixth of Earth’s. So you would weight about 1/6 of your current weight on the Moon

9. Mass/ Volume/ Density
Don’t be fooled! Which has a greater mass a kilogram of bricks or a kilogram of feathers?
Mass: the amount of matter in something
Measured using a balance or scale (g)
Volume: the space something takes up
Calculated by formula or displacement (L or cm3)
Density: How much stuff (mass) can fit in a certain amount of space
Density = Mass/Volume or D= m/v (g/mL or g/cm3)

10. Scientific Notation
We use this to write out very large numbers and very small numbers
Ex. The distance from Earth to Pluto is 4,500,000,000,000 m.
This number would be annoying to work with so we use a different form

11. Steps for Scientific Notation Changing from a regular number into scientific notation form
1st – move the decimal point to make a number between 1 and 10
Count the number of decimal places that you moved
Decide if you moved in a positive or negative direction
If moving the decimal makes the number smaller, it is going to have a positive exponent
If moving the decimal makes the number BIGGER, it is going to have a negative exponent

12. Example
5,000,000
We move the decimal place 6 places to the left to make the number 5
Our number got smaller as we moved the decimal point so we will have a positive exponent
Our new number is 5 x 106

13. Examples
1. 6,000
,000,000
= 6 x 103 = 3.5 x 107 = 5.6 x 10-3 = 9 x 10-7 = 1.23 x 10-4

14. Changing from Scientific Notation to a Regular Number
Determine how many places you must move the decimal (based on the exponent)
Determine which way to move decimal point
Right for a positive exponent (number must get bigger)
Left for a negative exponent (number must get smaller)

15. Examples
x 102
x 105
x 103
x 10-2
x 10-3
= 300 = 600,000 = 5500 = .034 = .0099

16. More Practice Solve and Answer in Scientific Notation
1. 6,000 x 1,000
2. 8,000 x 500
3. (6.5 x 102) (3.2 x 104)
4. (2.1 x 103) (6 x 104)
5. (7.5 x 10-4) (1 x 10-3)
= 6 x 106 = 4 x 106 = 2.08 x 107 = 1.26 x 108 = 7.5 x 10-7

17. Exit Ticket #9-12

18. 9. If you measure the volume of a container and get the same answer 4 times in a row, this is an example of:
Accuracy
Precision
Correctness
Luck

19. 10. If you measure the volume of a container and get a recording of 10
10. If you measure the volume of a container and get a recording of 10.2 mL and the actual volume is 10.2 mL, this is an example of:
Accuracy
Precision
Correctness
Luck

20. 11. If you travel to the moon, because of a change in gravitational force, this will change:
Your volume
Your height
Your mass
Your weight

21. 12. This a measure of the total amount of matter in something, despite the force of gravity:
Volume
Height
Mass
weight