In the addition problem below, some digits are missing, as indicated by the blanks. If the problem is done correctly, what is the sum of the missing digits?
___ 2 5
8 __ 8
1 6 ____
+_______________
__ 3 0 7
The sum of the missing digits is =
___ 2 5 missing digit = 3
8 __ 8 missing digit = 1
1 6 _ missing digit = 4
___________
_3 0 7 missing digit = 1
Proof
325
818
164
____
1307
+225 
