A
+ B B
______
A D D
A
+
B B
------------
A D D
ANSWER. A = 1; B = 9; D = 0.
CHECK
1
+
9 9
------------
1 0 0
S O L U T I O N
Since "A" is the leading digit of the sum, it is clear that A = 1.
Next, since a two-digit number BB after adding the "1" becomes a three-digit number ADD,
it is clear that BB is 99. Than for the sum ADD there is only one possibility to be 100.
A +BB ---- ADD You are adding a 1-digit number to a 2 digit number to get a 3 digit number, so the answer ADD can only be in the hundreds. So the first digit, A, of ADD, can only be 1. That means you could only have been adding 1. The only 2-digit number you can add 1 to and get a 3-digit number is 99. So: 1 +99 ---- 100 Edwin