1. Catalyst
Jaylan is conducting an experiment to see how the number of ice cubes affects the temperature of his water. When there is 0 ice cubes in his water, the temperature of the water is 72 °F. After he adds one ice cube, the temperature is 69 °F . And when he adds 3, the temperature decreases to 66 °F.
1. What is the independent variable?
2. What is the control group?
3. Create a data table to display his results.

2. Announcements
Tonight for Homework: Comparing Graphs Worksheet

3. Today’s Objectives
SWBAT use bar graphs, pie charts, and line graphs to represent data!

4. Data
Data are information in the form of measurements or observations.

5. Data Table Data tables are used to display our data. In a data table:
The independent variable is on the left
The dependent variable is on the right
You need to make sure that you include your units!

6. Studying vs. Assessment Score Independent Dependent Variable Variable
An Example
Studying vs. Assessment Score Independent Dependent Variable Variable
Units!!

7. Table Data  Line graph

8. Graphing- Why is it important?
Key skill used in math, science, business, social studies, reading
Useful for almost all jobs that pay well (medicine, law, business)
Big part of every standardized test (especially the ACT)
Necessary for class projects

9. Have you ever heard the saying…
“A picture is worth a thousand words!”

10. Why Use Charts and Graphs?
We use charts and graphs to help us communicate our results and conclusions
Sometimes, complicated information can be made easier to understand by providing an illustration

11. There are 4 Main Types of Graphs
1) Bar graphs
2) Line graphs
3) Pie charts
4) Scatterplots

12. Bar Graph Usually a bar graph is used to compare different groups
Useful for comparing data of several groups
Example: Popular Degrees to Get in College

15. Pie Chart or Circle Graph
Pie charts are used to show percentages of a whole at a set point in time
Show part: whole relationships
The “pie” is divided into different “pieces” of different sizes
The size of each piece represents a fraction or a percentage of the whole (100%)

16. Example: Favorite Musicians of 8th Graders

18. Line Graphs
A line graph is usually used to show how something changes over a short period of time
They have two different axes that each show a value for a variable
Within a line, graph, a point is plotted at each place where the values of two variables intersect
A line is used to connect all points
Line graphs are best used to show trends in data more clearly than tables

22. Line Graph vs. Bar Graph

24. Titling Graphs
Must communicate the dependent and independent variables
Can be presented in the form “Y versus X”
Some graphs need more descriptive titles than others
Score vs. Score
Final Score vs. Diagnostic Score
Relationship between Final Score and Diagnostic Score for 8th Grade Science
Brent Maddin *

25. Labeling the X and Y Axes
Independent (manipulated) variable is written along the horizontal axis (X axis)
Dependent (responding) variable is written along the vertical axis (Y axis)
Units on any variables should be included in parentheses (kg)
Brent Maddin *

26. Plotting Data Pairs as Points
Make sure the data table is in (X,Y) form
Select the first pair of values from the data table (X and Y).
Draw a light, dashed line up from the number on the X axis and over from the number on Y axis.
Where these light lines cross, put a dark point.
Repeat for the next pair of points.
Ask math teacher when they plot points during the year.
Get the language from the math teachers
Brent Maddin *

27. Numbering Axes STEP 1: Find the range for the variable
Range = Largest Value - Smallest Value
STEP 2: Divide the range by the number of intervals you have/want.
Round up to get a number that is easy to count by.
STEP 3: Mark off intervals on the axis, counting by the rounded number.
The interval must be the same amount each time
Brent Maddin *

28. So What?? Bar graphs are used to compare groups
Pie charts (circle graphs) are used to show part to whole relationship (percentages)
Line graphs are used to show trends over time

29. Student Misconceptions and Common Mistakes when Graphing
Brent Maddin *

30. Lets try it!
We will practice drawing a graph together!

31. Independent Practice
Begin working on your homework silently and independently
What you do not finish, will become homework to be turned in tomorrow