• Oct 14, 2025 maths matics trick _n_ is the number before 5. Multiply _n_ by (_n_ + 1). Append 25 to the result. Example: 75^2: _n_ = 7 7 × 8 = 56 Append 25: 5625 Result: 75^2 = 5625 Why it works: Mathematically, (10n + 5)^2 = 100n(n + 1) + 25, which simplifies to the pattern above. 2. The Magic of By Hilario Kertzmann
