Variables are values that change Variables are values that change. In algebra we represent variables letters such as x, y, z. Those letters represent data from the real world. Temperature (x) 50 60 70 80 90 100 # of fans sold (y) 1 2 5 15 25

Variables can be classified as either independent or dependent.

Dependent Variable The dependent variable DEPENDS on the independent variable. Example: Cost of restaurant bill Number of meals you ate Your bill at a restaurant depends on the number of meals you ate.

The dependent variable is always located on the y-axis of a graph. # NUMBER OF MEALS 1 2 3 $ Cost of meal $10 $20 $30 The dependent variable is always located on the y-axis of a graph.

Independent Variable The independent variable is the variable that comes first. Example: temperature # of fans sold The temperature determines how many fans will be sold.

The independent variable is always located on the x-axis of a graph. temperature 50 70 100 # of fans sold 1 5 The independent variable is always located on the x-axis of a graph.

D R I D X Y

A student’s grade & amount of time spent studying. _________________ depends on __________________ Independent variable:__________ Dependent variable:___________

Time spent exercising & number of calories burned. _________________ depends on __________________ Independent variable:_________ Dependent variable:___________

3. The amount of money you make and the number of hours you work. Independent variable: _____________ Dependent variable:_____________ 4. The number of sodas you buy and the total money spent. Independent variable:______________ Dependent variable:_______________ 5. The number of houses you can paint depends on how much time you have. Hours worked Amount of money Number of sodas Total money Amount of time Number of houses