Thread: Looking for a math site/software

I am looking for a math site or software that focuses on ratios, percentages and business math. That does not have to the sole focus of the site. What is important is that there needs to be a practice drill aspect of the site/software. Any recommendations are welcome.

A long time back I made up my own spreadsheets that generated worksheets in arithmetic and algebra [and the answers]. The key is to use random values so that a key press [F9] will regenerate a new sheet of exactly the same format but different numbers. It might require just a little effort, but is well worth it.