The Alice Dev Team (http://alicedev.com/) has introduces Handy Calculator 1.0 for Mac OS X (10.6.6 an higher). It’s an US$1.99 utility that allows users to input and check entire sequences of arithmetic operations, including parentheses, before pressing the “=” key.
Handy Calculator is available worldwide through the Mac App Store in the Utilities category. Designed as a real-world calculator for use with Mac apps, it features an oversized keypad and display window, white numerals on a black background, single click copying and pasting into and from the display, and 80% transparency when inactive.
Developer Stanislav Kuptsov says Handy Calculator has been designed for simplicity and style. Its oversize keypad and display, nearly half the height of the screen, makes input using a mouse easy, he adds.