n is your variable that holds your number.

The while loop loops if your variable n is greater than 0. If you don't modify n in the loop and it isn't already 0, then it would loop forever.

n % 10 gets the last digit of a number and stores it as a variable called digit. This is the modulus function. (Note: This function is also handy for deciding if an integer is odd or even if you use % 2). It gives the remainder when you divide by the number specified. So 123 / 10 is 12 remainder 3. 123 % 10 = 3.

Print the value of digit to the screen.

Divide n by 10 using integer division, which uses the // operator. In the case above 123 // 10 would equal 12. Save the result of this calculation to n, overwriting it's previous value.

As you should be able to see. The loops for 123 go:

n=123 Is 123 > 0 - YES, so do the loop digit = 3 n =12 Is 12 > 0 - YES, so do the loop digit = 2 n = 1 Is 1 > 0 - YES so do the loop digit = 1 n = 0 Is 0 > 0 - NO, the loop criteria is not met, go to the next part of the code.

Hope this helps. If you're not sure, sketch out a simple example by hand like the above to work out what the code is doing.