1. **State the problem:** The number of dance steps performed varies directly with the length of the music played. Given that 120 steps are performed in 3 minutes, we want to find what happens to the number of steps when the music length doubles. 2. **Formula for direct variation:** If $S$ is the number of steps and $t$ is the time in minutes, then $S$ varies directly with $t$, which means: $$S = kt$$ where $k$ is the constant of proportionality. 3. **Find the constant $k$:** Using the given values, $$120 = k \times 3$$ Divide both sides by 3: $$k = \frac{120}{3}$$ $$k = 40$$ 4. **Express the number of steps as a function of time:** $$S = 40t$$ 5. **Find the number of steps when the music doubles:** Doubling the music means time becomes $2 \times 3 = 6$ minutes. Substitute $t=6$ into the equation: $$S = 40 \times 6 = 240$$ 6. **Conclusion:** When the music length doubles, the number of steps also doubles from 120 to 240 steps.