# mathematics #mathpuzzle #maths ABCD+ABCD+ABCD+ABCD= DCBA

This video provides a step-by-step mathematical derivation to find a four-digit number $abcd$ that, when multiplied by 4, results in its reverse, $dcba$. Through a process of elimination and algebraic equations based on carry-over values, the presenter proves that the only number satisfying these conditions is 2178.