1. The problem asks which expression is equal to $\frac{6}{7}$.\n\n2. Let's analyze each option:\n\n- A: $6 - 7 = -1$, which is not equal to $\frac{6}{7}$.\n- B: $6 \times 7 = 42$, which is not equal to $\frac{6}{7}$.\n- C: $6 - 7 = -1$, same as A, not equal to $\frac{6}{7}$.\n- D: $6 \div 7 = \frac{6}{7}$, which matches the given fraction.\n\n3. Division of 6 by 7 is written as $\frac{6}{7}$, so option D is the correct answer.