In math, functions are widely employed and refer to a relationship that explains how two variables relate to one another. There are two variables: an independent variable that can be any input and a dependent variable that is the function’s output. 

So, what are functions?

“”Function, in mathematics, an expression, rule, or law that defines a relationship between one variable (the independent variable) and another variable (the dependent variable).”1

It would appear that functions, as described above, are either too complex or unrelated to be dealt with on a daily basis. Therefore, teaching children about functions through the concept of function machines might be effective. However, children will really begin to appreciate functions when they are able to apply them to real-life scenarios. So basically, any procedure that results in an output from an input is a function. Here are some illustrations:2,3

Vending Machines

vending machine

A vending machine is an automated device designed to offer customers a wide variety of goods, including snacks, beverages, cupcakes, newspapers, tickets, and more. Depending on the amount of money inserted and the product chosen, a vending machine will dispense a product to the users. The money and the chosen button serve as the input, and the products received serve as the output.



  • Temperature: Most thermometers have scales for both degrees Celsius and degrees Fahrenheit. Children can use a thermometer to understand how input and output functions work.
  • Weight: The amount of force applied to weighing scales allows them to calculate the weight. They then translate the outcome into mass and present it in different mass units, such as kilograms or pounds. Children can comprehend the functions of the weighing machine in a manner similar to how a thermometer works.
  • Distance: The mileage of a car, the duration of a falling object, and the cost of a taxi ride are all functions of distance in various everyday situations.

Mathematical Economics

Mathematical Economics

  • Remuneration: The hourly pay rate and the number of hours worked determine a person’s weekly or monthly salary.
  • Taxes and tax brackets: Another typical example of a function is the tax bracket. We can better understand the relationship between tax and taxable income by calculating the tax on a variety of different taxable incomes using functions.
  • Market value: When an input value crosses predetermined boundaries, a rule, or relationship changes, and we use functions to describe these circumstances. For instance, it frequently happens in business that the price per piece of a particular item is discounted once the quantity ordered exceeds a certain threshold.
  • Mortgage Payments: The inputs are the principal sum, interest rate, and duration of the loan or investment.

The mathematical building blocks of functions are used in the design of machines, the forecasting of natural disasters, the treatment of diseases, the study of global economies, and the maintenance of aircraft. Although they can receive input from numerous variables, functions always produce the same results that are specific to them.2 Every day, whether consciously or unconsciously, we use function to simplify various actions in our lives.


  1. function | Definition, Types, Examples, & Facts | Britannica. (n.d.). Retrieved August 19, 2022, from
  2. Functions in real Life. (n.d.). Retrieved August 19, 2022, from 
  3. APPLICATIONS OF FUNCTIONS IN DAILY LIFE by ilke yigiter. (n.d.). Retrieved July 27, 2022, from