Modulus and Floor Division
In case your mathematics is rusty, modulus means “left over”.
51 divided by 5 is 10.2 or 10 with 1 left over, the modulus is 1.
C:\Users\JohnO>python
Python 3.11.0 (main, Oct 24 2022, 18:26:48) [MSC v.1933 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> 51/5
10.2
>>> 51%5
1
>>> 51//5
10
>>>
Floor division is the other part, the result without the remainder, in this case 10.