i don't get the point of this single character printing.
when you have your long amps with 2 digits,
just cast calc to a float and let Print.h do it's job.
lcd.println(amps/100.0);when you want to add a 0 or a blank for lower numbers, print that 0/blank just before you print the value:
if(amps < 1000) lcd.print(' ');reserve more digits if you need to prepared for negative numbers.