Challenge Level: Ready to expand
This programming challenge is linked to the following lessons:
Students will be able to:
Write a program that asks the user to enter the first 12 digits of a product code, in one line of input, and works out the last digit as the output. For this challenge make sure the user can only enter a 13 digit product code (the first 12 digits).
Your program should display the outputs shown in this table for the given inputs provided:
| Input | Output |
|---|---|
| 941887000085 | The last digit is: 2 |
| 941527700012 | The last digit is: 6 |
| 930072885454 | The last digit is: 3 |
| 932835000371 | The last digit is: 9 |
Click on the green flag, enter the inputs provided in the “testing examples” to see the expected output of your program.
when green flag clicked
ask [Enter first 12 digits of the barcode:] and waitrepeat (6)
end
if <(length of (first 12 digits)) = [12]> then
else
endsay [You must enter a 12 digit number!]
say (join [The last digit of the product code is: ] (last digit))set [index v] to [1]
set [first 12 digits v] to [0]
set [total 1 v] to [0]
set [total 2 v] to [0]
set [last digit v] to [0]
set [last digit v] to (((0) - ((total 1) + ((total 2) * (3)))) mod (10))
set [first 12 digits v] to (answer)
set [total 1 v] to ((total 1) + (letter (index) of (first 12 digits)))
change [index v] by (1)
set [total 2 v] to ((total 2) + (letter (index) of (first 12 digits)))
change [index v] by (1)For the 12 digits entered, you need to add up 1st, 3rd, 5th and so on digits and store the result in a variable called "total 1". Then add up 2nd, 4th, 6th and so on digits and store the result in variable called "total 2". The last digit (check digit) is then calculated by subtracting the sum of "total 2" multiplied by 3 and "total 1" from 0 mod 10.
You can access a letter (or a digit) at a specified position in a string
(or number) by using the letter () of [] block under “Operators”.
For example: letter (4) of [18392819202910] //9
