The interest formula shows how interest, rate, and time are related. It gives you a way of finding one of these values if the other three values are known. Even though you try to be careful in your calculations, there will always be that occasion when you make an error and end up with an incorrect answer. You can avoid such errors by first predicting what a reasonable answer might be by estimating. As an example, if you have a 11.2% interest, you could use 11% to estimate what the correct result would be. Search the internet to find an application of simple interest that you find interesting, that you encounter on a daily basis or that you find in your profession.
a. How could you avoid an error by using a pre-estimation? Present this application to the class and explain why you choose the example.