I have found that the TI-83 series handles numbers remarkably better than many programming languages and even software packages. The built-in functions are diverse, composable, and very powerful, yet simultaneously simple to use. When I want to answer e.g., a statistics question, it's a huge time saver to plug it into the graphing calculator rather than anything else. I often prefer it even to WolframAlpha. In that respect it's well worth the $100 or so it cost.