View difference between Paste ID: nx7V46Ay and zWibfBYg

 local nprompt = function(q)
     print(q)
     term.blit("> ","3 ","  ")
     return tonumber(read())
 end
 
 local round = function(num)
     return math.floor((num*100)+0.5)/100
 end
 
 term.clear()
 term.setCursorPos(1,1)
 
-amntOfMonths = 12 --nprompt("Length of loan? (months)")
+local amntOfMonths = 12 --nprompt("Length of loan? (months)")
-monthlyPayment = nprompt("Monthly payment?")
+local monthlyPayment = nprompt("Monthly payment?")
-principle = nprompt("Principle?")
+local principle = nprompt("Principle?")
-interestRate = nprompt("Interest rate?")/100
+local interestRate = nprompt("Interest rate?")/100
-payoffMonths = nprompt("Payoff after how long? (months)")
+local payoffMonths = nprompt("Payoff after how long? (months)")
-totalMonths = nprompt("Total months of loan?")
+local totalMonths = nprompt("Total months of loan?")
 
-getIt = function(payoffMonths)
+local getIt = function(payoffMonths)
 
     output = {{}}
     output[1].interest = principle * interestRate * (1/amntOfMonths)
     output[1].principle = monthlyPayment - output[1].interest
     output[1].newPrinciple = principle - output[1].principle
 
     for a = 2, payoffMonths do
         output[a] = {}
         output[a].interest = output[a-1].newPrinciple * interestRate * (1/amntOfMonths)
         output[a].principle = monthlyPayment - output[a].interest
         output[a].newPrinciple = output[a-1].newPrinciple - output[a].principle
     end
 
     output[#output].principle = output[#output-1].newPrinciple
     output[#output].newPrinciple = 0
     finalPayment = output[#output].interest + output[#output].principle
     return output,finalPayment
 end
 
 local printOutput = function(output,finalPayment)
 
     local max = {}
     for a = 1, #output do
         max.interest = math.max(#tostring(output[a].interest), max.interest or 0)
         max.principle = math.max(#tostring(output[a].principle), max.principle or 0)
         max.newPrinciple = math.max(#tostring(output[a].newPrinciple), max.newPrinciple or 0)
     end
     for k,v in pairs(max) do
         max[k]=v+1
     end
 
     term.setCursorPos(1,1)
     term.write("Int.")
     term.setCursorPos(max.interest+1,1)
     term.write("Pri.")
     term.setCursorPos(max.interest+max.principle+1,1)
     term.write("NewPri.")
 
     for a = 1, #output do
         term.setCursorPos(1,a+1)
         term.write(round(output[a].interest))
         term.setCursorPos(max.interest+1,a+1)
         term.write(round(output[a].principle))
         term.setCursorPos(max.interest+max.principle+1,a+1)
         term.write(round(output[a].newPrinciple))
     end
 
     term.setCursorPos(1,#output+3)
 
     print("Final payment: "..tostring(round(finalPayment)))
 end
 
 local tab1, finalPay1 = getIt(payoffMonths)
 local tab2, finalPay2 = getIt(totalMonths)
 term.clear()
 printOutput(tab1,finalPay1)
 print("You saved: "..round(finalPay1-finalPay2))