Separating Digits in an Integer in C Language

Can someone explain to me how this code works? Like how the algorithm works?

Problem: (Separating Digits in an Integer) Write a program that inputs one five-digit number, separates the number into its individual digits and prints the digits separated from one another by three spaces each. [Hint: Use combinations of integer division and the remainder operation.] For example, if the user types in 42139, the program should print: "4 2 1 3 9"

#include<stdio.h>

int main(){

    int number, a, b, c, d, e, f;

    printf("Enter a 5-digit number: ");
    scanf("%d", &number);

    a = number;
    b = a / 10000;
    c = a / 1000 % 10;
    d = a / 100 % 10;
    e = a / 10 % 10;
    f = a % 10;

    printf("\n%d   %d   %d   %d   %d", b, c, d, e, f);

    return 0;
}