Science Starter: What is a topic that you have always been curious about? Write about why that topic interest you! Ms. Lang is interested in bioengineering. Which is the use of artificial tissues, organs, or organ components to replace damaged or absent parts of the body, such as artificial limbs and heart pacemakers.

Identifying Variables

Types of Variables There are 3 main types of variables: Independent Variable: The variable that is changed by the scientist; the variable ‘I change’ . Dependent Variable: The variable that might change because of what the scientist changes – what is being measured. Constant Variable: The variable that stays the same.

Key to variable success! Independent Variable (IV) = Use a BLUE Highlighter or color pencil Dependent Variable (DV) = Use a YELLOW highlighter or color pencil

Remember! Your hypothesis can TELL you what your variables are! Ex. If I drink Mountain Dew before bed, then I will not sleep very much. IV: Drinking Mountain Dew DV: the amount of sleep

Practice Use this hypothesis to identify the variables: If I leave all the lights on all day, then my electric bill will be expensive IV: ______________________ DV: ______________________

If Mrs. Strickler brushes her cats more, then there will be less fur on her furniture. IV: ______________________ DV: ______________________

If Ms. Lang brushes her husky more, then there will be less fur on her furniture. IV: ______________________ DV: ______________________

Now read the following experiment and identify the independent and dependent variables Elizabeth wanted to test if temperature affected how fast milk goes bad and curdles. She left milk in a room temperature closet, a fridge, and an oven that was turned on low heat. She then measured how rotten the milk was after 10 days. IV: ____________________________________ DV: ____________________________________

Other Variables: Constant Variable Variable that DOES NOT change.

Fudge Experiment : What’s the constant? Dorothy is making 3 batches of her world famous peanut butter Reese’s Pieces chocolate fudge. She is trying to make the most peanut buttery flavor fudge EVER! She puts together all her ingredients. For one batch she follows her previous recipe. For the second batch she doubles the amount of peanut butter. For the third batch she triples the amount of peanut butter and doubles the amount of Reese’s Pieces. For each batch, she uses the same container, temperature, and brand.