[Retric]

Think about basic math aka addition, subtraction, and multiplication work.

  1237 + 4567
  7+7 = 14 = 4
  3+6 + 1 = 10 = 0
  2+5+1 = 7
  1+4 = 5
  5704

That's right to left. If we wrote numbers left to right we the 1's place would be on the left.