“Maths Mate : Auto Algebra!” by jpoopdog solves simple algebra equation such as 3 + 5x = 13. The alpha version is being considered a bit buggy, but might be helpful for the one or other.

Thanks to http://nintendomax.com/viewtopic.php?t=13271&f=19 for the news.

http://dsgamemaker.com/dsgmforum/viewtopic.php?f=13&t=1580