Teaching the Common Core Math Standards With Hands-On Activities, Grades 3-5 (76 page)

4.
Now ask your students to model this problem. Create the model as a class, using the images on the next page to draw the model on the board.

• Explain that
  or
  is modeled below, showing 1 whole square and a quarter of another square. This represents the original amount of sugar.
  

  

• To model
  or
  (the expansion of the recipe), draw the previous model again, right below the original. This will result in 4 squares. Divide each square into 2 rows (which divides each square into 8 equal parts) and shade 3 of the rows. The 15 parts that are darkly shaded represent the product of
  , which is
  or
  .Remind your students that they are multiplying
  by
  . Multiplying the denominators produces eighths.
  

  

5.
Explain that Mandi's punch recipe contains three more ingredients in addition to the sugar.

6.
Explain that students are to increase the amount of each of the other three ingredients by
. They are to write an equation and draw a model that represents the problem, and then solve the problem. They should show their work on the reproducible and draw their model on graph paper.

Closure

Check your students' work. Discuss any of the problems they found to be difficult. Ask which of the problems was easiest to model. Which was the hardest? Why?

Answers

Models will vary but should represent the problems and the following answers.
(1)
cups
(2)
cups
(3)
pints
(4)
cups