Think of gravity like a pulling force; since the moon is smaller and less massive, it pulls on objects with less intensity than the Earth, making them feel 'lighter' while their actual material content (mass) stays exactly the same.

The weight of an object is given by the formula $W = m \times g$. Because mass remains constant regardless of location but the gravitational acceleration on the moon ($g_{moon}$) is $g_{earth} / 6$, the weight on the moon becomes $W_{moon} = m \times (g_{earth} / 6)$, which simplifies to $W_{moon} = W_{earth} / 6$.

Always remember that mass is a scalar quantity measured in kg, while weight is a vector force measured in Newtons (N). If a question mentions 'mass' on the moon, it will be the same as on Earth!