Equation: STILL + HAS = TRUTH. Each of the 8 unique letters (A, H, I, L, R, S, T, U) represents a different digit. Leading letters (S, H, T) cannot be zero.

S=8, T=9, I=7, L=6, H=4, A=2, R=0, U=1 → 89766 + 428 = 90194

STILL + HAS = TRUTH

What is this puzzle?

Solve the addition alphametic puzzle where STILL + HAS = TRUTH. 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 (A, H, I, L, R, S, T, U). In the equation STILL + HAS = TRUTH, 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 S and H and T cannot represent zero — this is your first constraint. To solve this efficiently, focus on letters that appear in multiple positions across the equation — these are the most constrained and often the easiest to determine first.

This addition alphametic has 8 unique letters to determine.
Leading letters: S, H, T. 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.