My project involves a portable cancer diagnosis system, where the user keys in 4 fixed/floating point values and calculates whether the person has cancer or not. Up to now I can get the keypad and LCD functioning. But the calculations are giving me a headache. First of all I need to convert what the user keyed in (through the keypad) to a 8051 understandable format, which is either decimal or hex. It is easier to convert it into decimal because it won't affect the floating point position. However when I multiply it with other decimal numbers, the carry part is a problem because the 8051 assumed that both numbers are in hex form. So, it can only detect carry in hex form. Any suggestions? Thanx.