HE
SET
THE
----
TEST
The sum is 4 digits; the addends are all 2 or 3 digits; so T must be 1.
HE
SE1
1HE
----
1ES1
In the units column, E+1+E yields sum 1, so E is either 0 or 5. But E=5 as the second digit of the sum is not possible, so E is 0.
H0
S01
1H0
----
10S1
In the hundreds column, S+1 plus possibly a carry of 1 yields 0, so S is either 8 or 9. But in the tens column, H+0+H yields S, so S is even. So S is 8.
H0
801
1H0
----
1081
ANSWER: TEST = 1081
Note that we can get some more practice with logical reasoning by finishing the addition problem.
In the tens column, H + 0 + H yields 8, so H is either 4 (4+4=8) or 9 (9+9=18). But in the hundreds column a carry of 1 is needed, so H is 9.
90
801
190
----
1081