You can use your Firefox as calculator too, beside for browsing. It's not default feature on Mozilla Firefox but you should install addition add-on to active this feature. This add-on is Status-bar Scientific Calculator. It will install calculator on Firefox status bar. It means you can use calculator from Firefox status bar. Using this add-on, you don't need to open Calculator program anymore. The beautiful thing that this add-on offers scientific calculator not only simple calculator.
Using this is simple. Just type in the values like in a normal calculator, and keep in mind that you need to use brackets to change the processing order. The calculator supports all basic operations plus a lot of advanced operations that involve complex numbers. Among those are switching from decimal and hexadecimal to all other bases from 2 to 24
The add-on supports up to ten digits after the decimal point, with options to increase or decrease that number in the settings.