' version 25-10-2016
' compile with: fbc -s console

' Charles Babbage would have known that only number ending
' on a 4 or 6 could produce a square ending on a 6
' also any number below 520 would produce a square smaller than 269,696
' we can stop when we have reached 99,736
' we know it square and it ends on 269,696

Dim As ULong number = 524 ' first number to try
Dim As ULong square, count

Do
    ' square the number
    square = number * number
    ' look at the last 6 digits, if they match print the number
    If Right(Str(square), 6) = "269696" Then Exit Do
    ' increase the number with 2, number end ons a 6
    number = number +2
    ' if the number = 99736 then we haved found a smaller number, so stop
    If number = 99736 Then Exit Do
    square = number * number
    ' look at the last 6 digits, if they match print the number
    If Right(Str(square),6 ) = "269696" Then Exit Do
    ' increase the number with 8, number ends on a 4
    number = number +8
    ' go to the first line under "Do"
Loop

If number = 99736 Then
    Print "No smaller number was found"
Else
    ' we found a smaller number, print the number and its square
    Print Using "The number = #####, and its square = ##########,"; number; square
End If


' empty keyboard buffer
While Inkey <> "" : Wend
Print : Print "hit any key to end program"
Sleep
End