1. Math in Science
In science we use the metric system to make measurements in the lab
The basic unit of the metric system include:
Gram (mass)
Liter (volume)
Meters (length)
Lets practice converting with in the metric system
First to remember the order
King
Henry
Died
Drinking
Chocolate
Milk
Now lets look at the ladder that will help you convert between these measurements.
See Metric Mania PowerPoint on site! 

2. Math in Science Some tools that allows us to ANALYZE data:
Weight- measure of the force of gravity working on you
Unit is the Newton (N)
Mass- how much matter is in an object (units g, kg, mg)
Describe what we would find if we compared weight and mass on the moon.
Volume- the amount of space something takes up
Formulas:
Regular solid: (flat sides) L x W x H
Measured using ruler, meter stick, etc.
units in length ie. m3, cm3, mm3
Irregular solid (a rock): WATER DISPLACEMENT (method on p. 61)
Measured using a graduated cylinder
units in volume ie. L, mL
Density- how much mass is in a given volume
D = m/v (mass/ volume)
units kg/m3 or g/mL or g/cm3
Density can be used to determine if an object will sink or float.
Density of water is 1.0 g/cm3
if the object is more than 1.0 g/cm3 it will sink
if the object is less than 1.0 g/cm3 it will float
Density Triangle
Use if given two of three variables
Video

3. Mathematics and Scientific Thinking
Math Skills that Scientist Use when they analyze data:
Estimation- approximation of a number based on reasonable assumption
Accuracy vs. Precision
Accuracy- how close the measurement is to the true value
Precision- how close a group of measurements are to each other
high quality tools yield results that are accurate and precise.
Tools that analyze data
Mean- average
Median- middle number
Mode-number that appears most often
Range- difference between greatest and least value
What if you cannot observe the subject you are studying directly?
Model- any representation of an object or process
Usually of things that are very small or very large
Often used to represent systems- group of parts that work together to carry out a function

4. Graphs and percent error
Do now-
How do scientists use graphs in science?
Why are graphs useful?
Identify trends
Make predictions
Recognize anomalous data
Anomalous data- a data point that does not fit with the set,
caused by human or equipment error or if neither of those
Is an outlier on the graph

5. Time to practice Create a graph for the data below:
Average daily temperatures for January 1st-7th
What kind of graph would you create?
Line graph
Used to show a change over time
Shows how dependent variable changes in response to
independent variable
Linear-straight line
Nonlinear-not straight line
Outlier-data point not part of trend, anomalous data
***If a graph does not have a clear trend,
it usually means the variables are not related
Date
Temperature 0F 1 10 2 25 3 30 4 42 5 23 6 7 40

6. Time to practice Create a graph for the data below:
Favorite After school activities
What kind of a graph would you create?
Bar Graph
Comparison of things, one time event,
good for surveys
Activity
Number of students
Hang out with friends
175
Talk on phone
168
Play sports
120
Earn money at part time job
Play video games 65

7. Time to practice Create a graph for the data below:
Composition of Earth’s crust
What type of graph would you create?
Pie Chart
Good when determining how many parts,
a percentage
Element
Percentage
Oxygen
49.5
Calcium
3.4
Iron
4.7
Aluminum
7.5
Silicon
25.7
Other
9.2

8. Time to practice Create a graph for the data below:
Test score variation due to hours slept
Scatter plot
Use to determine of there is a correlation between two variables

9. Computer Graphing Programs
When ever possible your graph should be done using the computer
Here is a great site:
Microsoft excel also has a graphing function that you can use
When creating graphs you must include
A title
Labels on all axis (and units)
A key (when needed)
Multiple lines should be differentiated—symbols for points, colored lines

10. Percent Error (in a nutshell)
Accuracy- how close you are to the accepted value
Precision- how close a group of measurements are to each other
Percent Error- how close or far you were from the actual accepted value
Low percentage = accurate results
Percent Error = your value - true value (given) X
true value
Lets try an example, calculate the answer to the question on page 72
Lets do one more….
A student calculated the density of tin to be 7.20 g/mL.The actual density of tin is 7.29 g/mL. What is the percent error? Is this accurate?
Answer = 1.23% Yes, this is accurate