Find the Opposite Number: Determining the Negative of 49

To solve this problem, we need to find the reciprocal of $49$ because the problem refers to the "opposite number," in this context, likely meaning its multiplicative inverse.

Here are the steps to find the solution:

• Step 1: Start with the given number, which is $49$.
• Step 2: Apply the formula for the reciprocal. The reciprocal of a number $a$ is $\frac{1}{a}$.
• Step 3: Substitute $49$ for $a$ in the formula, resulting in the reciprocal being $\frac{1}{49}$.

Thus, the reciprocal or "opposite number" of $49$ is $\frac{1}{49}$.

To confirm with the answer choices, the correct choice is $\frac{1}{49}$.

Therefore, the solution to the problem is $\frac{1}{49}$.