Eigenmath

Eigenmath is a program designed for Mac users who wish to make basic as well as advanced math calculations on their computers.

Unlike Mac's default Calculator app, this utility doesn't provide you with a numpad screen; instead, it allows you to write your equations like you'd do it on paper.

The application features an integrated help guide that teaches you how to write complex equations. You can also find a very useful manual on the homepage of the developer that offers you equation examples, theorems, syntax information, and many others.

After you write your equation, you simply click the Run button and the utility immediately shows you the result on the right side of the page. The program keeps track of previous equations in case you need to re-use them again.

Another advantage is the fact that you can export your results to your local drives. Furthermore, you can print the problems' answers directly from the app's interface.

To conclude, I'd say it's worth installing Eigenmath on your Mac if you need a capable utility for solving math problems. In addition, it's free of charge.