Solve 23 + Box = ?: Simple Variable Substitution Problem

To solve this problem, we will follow these steps:

• Step 1: Recognize that the unknown represented by the yellow box is given as 12.
• Step 2: Set up the addition equation using the information given: $23 + 12$.
• Step 3: Perform the addition.
• Step 4: Match the result with one of the provided choices.

Now, let's perform the calculations:
Step 1: Interpret $\text{yellow box} = 12$ as $12$.
Step 2: The expression we need to solve is $23 + 12$.
Step 3: Calculate the sum:
$23 + 12 = 35$.

We find that the sum of 23 and 12 is 35.

Therefore, the solution to the problem is $35$, which corresponds to choice number 2 in the given options.