1. **State the problem:** Simplify the expression $\sqrt{6} + \sqrt{6}$.\n\n2. **Recall the rule:** When adding like terms, you add their coefficients. Here, $\sqrt{6}$ is like a term, so $\sqrt{6} + \sqrt{6} = 2 \times \sqrt{6}$.\n\n3. **Apply the rule:**\n$$\sqrt{6} + \sqrt{6} = 2\sqrt{6}$$\n\n4. **Final answer:** The simplified form is $2\sqrt{6}$.