Math Background

Functions: When Students Ask

  • Why should I learn about functions?
    Explain that functions help you to understand the relationship between variables. If you know how many cups of flour are needed to make one batch of cookies, you can determine how many cups are needed for x number of batches. Or if you know how many of a certain color bead are needed to make one bracelet, you can figure out how many are needed for x number of bracelets. When you are shopping, understanding functional relationships can help you compare similar items to see which costs less per pound, per gallon, and so forth.

    Remind students that functions are used to describe the relationship between variables in science as well as math. Guide students to recall a science experiment that they have done involving variables. If possible, show them a data table or a graph from that experiment and have them describe in general terms the relationship between the variables.

    Explain to students that understanding simple functions will help them understand more complex algebra and functions later on.

  • When will I need to use functions or function tables?
    Show students examples of function tables relating to daily life. Examples include a table showing the distance traveled over a certain amount of time, a table showing the hourly cost for parking in a garage or at a meter, or the table from a pancake or rice package specifying how much mix or rice to use depending upon the number of servings desired. Tell students that they can also use the information in function tables to create graphs that depict the relationship between variables.

Houghton Mifflin Math Grade 5