The float precision is about 7 digits, thus you should not have problems with 10000 and 0.05 - but with 100000 and 0.05 this error would appear, for sure.
If you must work with such wide range of values, declare the variables as double:

var money: double = 1000000;
var bet: double = 0.05;

Double precision is about 16 digits, thus the player can even break the bank without loosing precision.