Skins » Productivity » Equalizer :

Equalizer Skins

Equalizer is a freeware scientific calculator. Instead of the traditional look of many buttons, Equalizer has a simple text line on which you can write the expression in the same way you´d write it on paper (for example: typing "(6*5-12) / 2" will show the answer "9"). In addition, Equalizer is fully skinable - you can completely change its appearance, and even create your own skins.