The St. Louis fourth and fifth grade students in Ms. Shuey’s Title I math class used the technique of visualizing volume to estimate and determine the number of Skittles in a 3-dimensional rectangular prism.

They wanted to win the Guess the Number of Skittles Contest!

skittles borderGuess the Number of Skittles Contestskittles border


Visualizing Volume to Estimate and Determine the Number of Skittles

The following are the students’ work and their discoveries:

  • First we made a ball park estimate. Our estimate was 200 Skittles. That was OK, but we wanted an exact number.
    ball park estimate of 200.



  • The second step was to count the number of Skittles in the 3-D rectangular prism.
    count the number of Skittles in the rectangular prisim
  • Thirdly, we worked to VISUALIZE this:
    visualizing volume
  • For the fourth step, we learned to deconstruct the rectangular prism into layers.
    The h = the number of layers.
    Then find the area (l x w) of each layer.
    deconstruct the layers
  • During the fifth step, we learned the easiest way to figure it out: How to find the volume of a Rectangular Prism!
    visualizing volume of a rectangular prism