TolpuddleSartre:
Don't use floating point, use integers, but work in units of 1mm (or tenths of a mm if you need to work to two decimals of a cm)
You are talking about this?
void checknumber(float x){
if (firstnumber == 99) { // Check if this is the first number entered
firstnumber=x;
String displayvalue = String(firstnumber); // Transform int to a string for display
drawnokiascreen(displayvalue); // Redraw Nokia lcd
Because is the only place where i think i am defining as a float , the variable.
sorry if i am wrong but, you are talking about that i have to write it like this ?
void checknumber(int x){
if (firstnumber == 99) { // Check if this is the first number entered
firstnumber=x;
String displayvalue = String(firstnumber); // Transform int to a string for display
drawnokiascreen(displayvalue); // Redraw Nokia lcd