Solve:
1 + 0 = ?
4 + 0 = ?
3 + 0 = ?

do you get it?​

Anything plus 0 is equal to the number it was plus by.
Example: 15 + 0 = 15
4 + 0 = 4
1 + 0 = 1
3 + 0 = 3
Anything multiplied by 0 is equal to 0.
Example: 15 x 0 = 0

Anything divided by 0 is equal to 0.
Example: 15\ 0 = 0

Anything subtracted from 0, is equal to what was subtract from 0.
Example: 15 - 0 = 15

Dwould be the answer

The first digit is in the middle school 100s place