Independent and Dependent Variables

Sarah is bringing treats to her elementary school class on her birthday. The number of treats she brings in is based on the number of students in her class.

t = the number of treats

s = the number of students

Which of the variables is INDEPENDENT?

• s

• t

Sophie earned $5 for every A she got on her report card.

m = money

A = A on report card

The dependent variable is:

• m = money

• A = A on report card

Independent means

• an amount that can stand on its own
• an amount that depends on another amount

Jimmy earned $8 for every pizza he delivers.

m = money (dollars)

p = number of pizzas delivered

The dependent variable is:

• m = money

• p = number of pizzas delivered

Emma gets one sticker for every paper she completes.

s = stickers earned

p = papers completed

The independent variable is:

• s = stickers earned

• p = papers completed

Ty earns $12 per hour. Which of the following equations best represents how much money, m, he earns on a shift of h hours?

• m = 12h

• m = 12 + h

• h = 12m

• h = 12 + m

Ms. Shi is making a scrapbook. As she adds more photos, the scrapbook grows thicker.

p = the number of photos added

t = the thickness of the scrapbook

• t is the independent variable and p is the dependent variable

• p is the independent variable and t is the dependent variable

An experiment is performed on plants to see how different liquids affect plant growth. Each plant in the experiment is given a different liquid; water, apple juice, or milk.  In this investigation, the independent variable is ...

• The type of plant
• The amount of sunlight
• The type of music
• The type of liquid

Mrs. Ahlers set up an experiment to see how the mass of a ball affects the distance it rolls off a ramp. What is the dependent variable?

• Distance traveled by the ball
• Height of the ramp
• Mass of the ball
• Where the experiment took place.

Jonathan set up the same experiment to see how the mass of a ball affects the distance it rolls off a ramp. Identify the independent variable.

• Distance traveled by the ball
• Height of the ramp
• Mass of the ball
• Who set up the experiment (Jonathan etc)