How do you complete level 15 on 100 Floors?

The logic behind this level is that the part of the figure that is missing is where the number is on the keypad, so for the first figure over the door, the upper left corner is missing, where the number 1 is on the keypad. For the second figure, the right middle is missing, which is where the 6 is, etc.

Type in the pass code 1643 to open the door.