The puzzle has spread widely online precisely because it exposes a gap between how intuitive mental math feels and how formal mathematical rules actually work. Seeing a string of additions, subtractions, multiplications and divisions, many people default to reading the equation like a sentence — left to right, one step at a time.
PEMDAS: the rule that decides everything
Solving the puzzle correctly depends entirely on following PEMDAS — the standard order of operations in mathematics. The acronym stands for Parentheses, Exponents, Multiplication, Division, Addition, Subtraction.
The rule establishes a strict hierarchy: operations inside parentheses are resolved first, then exponents, then multiplication and division (handled together, from left to right), and finally addition and subtraction (also left to right). Skipping or reordering any of these steps produces a wrong answer.
PEMDAS is taught in schools precisely because human intuition tends to process sequences linearly. The rule overrides that instinct and imposes a consistent, universal method — which is why the same equation always produces the same result, regardless of who solves it.
What PEMDAS actually is
PEMDAS is the standard mnemonic used in mathematics education to define the order in which operations must be performed in any equation. It stands for Parentheses, Exponents, Multiplication, Division, Addition, Subtraction. Multiplication and division share the same priority level and are resolved left to right, as are addition and subtraction.
Step by step: how 55 becomes the only correct answer
Applying PEMDAS to the equation, the first move is to handle multiplication and division from left to right. That means 7 × 7 = 49 comes first, followed immediately by 7 ÷ 7 = 1. After these two operations, the equation simplifies to 49 – 1 + 7.
