Please help a noob :D

Could some 1 tell me why oh why this doesn’t work, please?

_root.position = Number(_root.position)+(_root.xvalue-350)/(_root.Distance.distance);

but this does

_root.position = Number(_root.position)+(_root.xvalue-350)/10;

Its for a game, which I need to get progressively harder. I can do this by increasing the distance value but it’ll only work with a number (ie 10).

Please help me?