Problem

Methanal reduction is about adding hydrogen to a carbonyl group—the key is recognizing what product forms and then balancing atoms and charge systematically. Start by identifying the oxidation state of carbon in $\text{HCHO}$ and in the reduced product (usually methanol, $\text{CH}_3\text{OH}$), then write the skeleton equation and balance oxygen with water, hydrogen with $\text{H}^+$, and finally electrons. This forces you to see reduction as electron gain in the half-equation framework.

Methanal reduction is about adding hydrogen to a carbonyl group—the key is recognizing what product forms and then balancing atoms and charge systematically. Start by identifying the oxidation state of carbon in $\text{HCHO}$ and in the reduced product (usually methanol, $\text{CH}_3\text{OH}$), then write the skeleton equation and balance oxygen with water, hydrogen with $\text{H}^+$, and finally electrons. This forces you to see reduction as electron gain in the half-equation framework.