Objectives

Students will be able to

• describe probability as likely, unlikely, impossible, or certain
• use a fraction to express probability

• Determine prior knowledge- review fractional parts and equivalent fractions
• Examine the cubes in the jar and discuss the likelihood of reaching into the jar and pulling out the red cube. Demonstrate by pulling all the cubes out one at a time without looking and writing the outcomes on the board: W(white) Y(yellow) B(blue) B(blue) G(green) O(orange) R(red). The event of randomly choosing a red cube from the jar occurred 1 out of 8 times.
• Discuss the likelihood (impossible/certain, unlikely/likely) of choosing the red cube. The likelihood of choosing the red cube on the first draw is unlikely.
• Repeat activity for other colored cubes. Find the likelihood of choosing a cube that is not red: 7/8 likely; yellow: 2/8 unlikely; black: 0/8 impossible.

• Define terms likely and unlikely at the white board and ask students to copy the definitions in their journals. Work with students to come up with an example for each. Wearing shorts in the winter is unlikely.   Having homework each night is likely. 
• Define equally likely. In Mrs. Field’s classroom, there are 24 students. Of the students, 12 are boys and 12 are girls. If Mrs. Fields randomly calls upon one student, it is equally likely that she calls upon a boy or girl.
• Discuss the outcomes of the cubes and jar again. What is the likelihood of choosing a blue or a white cube? (Both are 2/8, therefore it is equally likely I could choose a blue cube or a white cube.)

• Continue to practice various problems together at the board with students.
• Ask students to work individually to find answers to various problems. Ask students to pair up with a partner and discuss their answers.
  • Ideas for various problems:
    •  Find the probability a coin will land on heads/tails.       
    •  Find the probability that a die will roll an odd/even number; roll a number greater than 3.
    •  Find the probability of rolling the number 7 on the die.
    •  Find the probability of a spinner landing on blue, the probability of spinning either red or blue, etc.
    •  Sketch a spinner where the probability of spinning the color red is 1/3.

• Ask each group to share their results either orally or at the board.
• Ask pairs of students to create more probability problems for other pairs to solve, and check each other’s work.

• Ask students to consider a number line (0-100) with probability. An event that occurs 0% of the time is impossible, an event that occurs 100% of the time is certain. An event where the outcome is 50% is equally likely. 
• Ask students which numbers on this number line correlate to the words impossible (0%), unlikely (between 0 and 50), equally likely (50%), likely (between 50 and 100), and certain (100%). 
• Draw the number line with the students at the board, and ask students to copy this into their journals.