In today’s post we’re going to talk about the concepts of **Constants and Variables** as mathematical elements, as well as taking a look at an example.

In mathematics, we call **constant** all those magnitudes that don’t change with time. It can sometimes be a fixed and determined value.

On the other hand we have the concept of the **variable**, which is used to define any quantity susceptible to taking different numerical values.

To better understand the difference between both concepts, we’re going to use the following situation as a reference.

**Mary and Roger are taking a road trip. Since the road is clear, they’ve been able to travel at a speed of 60 miles/hr for the last half an hour.**

Since their speed has been the same for the whole of the last half an hour of the trip, we can say that the speed of Mary and Roger’s car has been **CONSTANT**.

For this to have happened, the car engine has had to exert different thrust forces. In other words, the engine has not had to exert much force during the downhill parts of the journey in order to maintain a speed of *60 miles/h. *But, on the other hand, the engine has had to exert much more force on the uphill parts in order to keep the speed constant.

This means that the thrust force that the engine has exerted is a **VARIABLE**, because it has changed during the journey.

After this you will have noticed that most of the magnitudes or measures that we take are usually variable. But, if you think about it you will be able to find some constants…

I hope that this example has helped make these two concepts a little clearer! Log in to Smartick and discover what magnitudes we use in our exercises or practice problems involving constants and variables.

Learn More:

- Inverse Proportionality: What Is It?
- Angles Explained with Clockhands
- Division Problems: Different Models and Examples
- Direct Proportions: What Are They? What Are They Used For?
- Ratio and Proportion: Concept and Some Examples