Equation: NOT + THIS = YOUTH. Each of the 8 unique letters (H, I, N, O, S, T, U, Y) represents a different digit. Leading letters (N, T, Y) cannot be zero.

N=7, O=0, T=9, H=5, I=8, S=6, Y=1, U=2 → 709 + 9586 = 10295

NOT + THIS = YOUTH

What is this puzzle?

Solve the addition alphametic puzzle where NOT + THIS = YOUTH. Each letter represents a unique digit from 0-9. No number starts with zero.

Difficulty: medium · Category: addition · Unique letters: 8

This medium-level addition alphametic puzzle features 8 unique letters (H, I, N, O, S, T, U, Y). In the equation NOT + THIS = YOUTH, each letter maps to a distinct digit from 0 to 9. With only 8 of 10 digits used, 2 digits remain unused in the solution. The leading letters N and T and Y cannot represent zero — this is your first constraint. The result "YOUTH" has more digits than any addend, which means there must be a carry into the leftmost position. This is a crucial clue for determining the result's leading letter.

This addition alphametic has 8 unique letters to determine.
Leading letters: N, T, Y. None of these can be zero.
There are 8 unique letters, so 2 digits from 0–9 will not be used.
Start from the rightmost column (units place) and work left, tracking carries between columns.
With two addends, each column can produce a carry of at most 1.
A moderate number of letters means you'll need logical deduction alongside trial and error.