Lesson Plan # 7 - Fraction multiplication

  1. (5 min) Mental Math
    1. Start with 30, subtract 12, then divide by 3 [6]
    2. What is 30 times 4? [120]
    3. What is 30 times 40? [1200]
    4. What is 30 times 400? [12000]
    5. What is 300 times 4? [1200]

  2. (5 min) Review of selected problems from Homework # 6 (<= 3 problems)
  3. (15 min) Introduce fractions:
    1. Discuss what a fraction is: a part of a whole, a number between zero and 1. It has a numerator and a denominator. The denominator is the number of parts the whole is cut up into. The numerator is the number of those parts that you have. Illustrate with a pizza drawn on the board. Cut the pizza into 8 pieces and ask students how many pieces they can eat.
    2. Handout the "Fraction rules" handout and discuss the following concepts (go through the examples for each):
      1. Fraction multiplication
      2. Converting mixed numbers to improper fractions
    3. Have students turn over the handout to the "Area of a triangle" discussion and discuss the fraction version of the triangle area formula. Have them work the first fraction example near the bottom of the page.
  4. (Remainder of class) In-class Exercise.
  5. Hand out homework as students successfully complete the in-class exercise.