1. Let's state the problem: Why do we multiply $m_1$ times $m_2$ in certain formulas, such as Newton's law of universal gravitation? 2. The formula for the gravitational force between two masses is: $$F = G \frac{m_1 \times m_2}{r^2}$$ where $F$ is the force, $G$ is the gravitational constant, $m_1$ and $m_2$ are the masses, and $r$ is the distance between them. 3. The multiplication $m_1 \times m_2$ represents the combined effect of both masses on the gravitational force. Each mass contributes proportionally to the force. 4. Think of it like this: the force depends on how much mass each object has. If either mass is zero, the force is zero, which makes sense physically. 5. So, multiplying $m_1$ and $m_2$ captures the interaction between the two masses, showing that the force increases as either mass increases. 6. This is a common principle in physics where interactions depend on the product of properties of two objects. Final answer: We multiply $m_1$ times $m_2$ because the force depends on the combined effect of both masses interacting, and multiplication captures this proportional relationship.