Functional Relationships

When introducing functional relationships, it is important for children to see the need to learn how these concepts can be of help outside the classroom. Making these connections gives students the need to learn mathematics. If we can show children how the mathematics can benefit them, the learning of the concepts becomes much easier.

Materials: paper and pencil for each student

Preparation: Copy the following table on the board.

• Introducing the Concept
• Developing the Concept

Prerequisite Skills and Concepts: basic division facts

• Ask: How many people like popcorn?
  Food is always a good hook to entice student learning.

• Ask: If you were going to buy popcorn at the store, which brand and size box would you buy? Why did you make this choice?
  Have each student write down their answer and reason on a sheet of paper.

• Have each student copy the above table onto their paper.

• Ask: What things did you think about when you made your decision?
  This will spark a class discussion. Some children will make their choice based on the number of packages in the box; others will say the price.

• Ask: Does it matter how much the popcorn costs? Why?
  Some students may say they shop for the lowest price. Others may say it doesn't matter.

• Ask: Should you always buy the least expensive box? Should you always buy the largest box?
  No. It depends on the cost. The goal is to enter a class discussion on the importance of the cost of each package of popcorn.

• Ask: What are we buying?
  Popcorn

• Say: We need to know the cost of each package of popcorn to determine which box to buy. To determine this, divide the cost of the popcorn by the number of packages in the box. This will give us the cost of each package. Fill out your table.
  

• Ask: Which brand of popcorn is the best buy? Why?
  Brands B and C are the best buy because they cost $1 per package.

• Although the class has determined which brand is the best buy, it might also be a good idea to discuss other factors that are important to people such as:
  

  Which brand has larger packages of popcorn?
  Which brand tastes better?

  Have a class discussion regarding why these factors might also be considered.