Equation: ISNT + THIS + FUN = STUFF. Each of the 7 unique letters (F, H, I, N, S, T, U) represents a different digit. Leading letters (I, T, F, S) cannot be zero.

I=9, S=1, N=2, T=3, H=7, F=6, U=5 → 9123 + 3791 + 652 = 13566

ISNT + THIS + FUN = STUFF

What is this puzzle?

Solve the addition alphametic puzzle where ISNT + THIS + FUN = STUFF. Each letter represents a unique digit from 0-9. No number starts with zero.

Difficulty: medium · Category: addition · Unique letters: 7

This medium-level addition alphametic puzzle features 7 unique letters (F, H, I, N, S, T, U). In the equation ISNT + THIS + FUN = STUFF, each letter maps to a distinct digit from 0 to 9. With only 7 of 10 digits used, 3 digits remain unused in the solution. The leading letters I and T and F and S cannot represent zero — this is your first constraint. This puzzle has 3 addends (ISNT + THIS + FUN), making carry analysis more complex. Start from the rightmost column and work left, tracking carries between columns.

This addition alphametic has 7 unique letters to determine.
Leading letters: I, T, F, S. None of these can be zero.
There are 7 unique letters, so 3 digits from 0–9 will not be used.
Start from the rightmost column (units place) and work left, tracking carries between columns.
With three addends, each column can produce a carry of at most 2.
A moderate number of letters means you'll need logical deduction alongside trial and error.