In the following sum, which digit does the symbol “*” stand for ? *2 + * + 1*…

Concept: When the same masked symbol stands for one fixed digit throughout a sum, assign that digit a variable and rebuild every masked number by place value (tens digit × 10 + units digit). This turns the puzzle into a single linear equation in one unknown, restricted to 0–9.

Application:

1. Let the digit represented by “*” be x, where 0 ≤ x ≤ 9.

2. Rewrite each masked term by place value: *2 = 10x + 2; * = x; 1* = 10 + x; *0 = 10x.

3. Rewrite the right-hand side the same way: 1** = 100 + 10x + x = 100 + 11x.

4. Add the left-hand terms: (10x + 2) + x + (10 + x) + 10x = 22x + 12.

5. Equate both sides: 22x + 12 = 100 + 11x, so 11x = 88 and x = 8.

Cross-check: Substituting x = 8 back into every term: 82 + 8 + 18 + 80 = 188, and the right-hand side 1** with x = 8 reads 188 — both sides match, confirming the digit.

So the symbol “*” stands for the digit 8.