In this experiment, the probability of selecting the card labeled "5" in a single trial is \( \frac{1}{10} \) since there are 10 cards, each equally likely to be chosen.
If the experiment is repeated 120 times, the expected number of times the card "5" is selected can be calculated using the formula:
\[ \text{Expected number of selections} = \text{Number of trials} \times \text{Probability of selecting 5} \]
Substituting the values:
\[ \text{Expected number of selections} = 120 \times \frac{1}{10} = 12 \]
Therefore, you can expect to select the number 5 approximately 12 times in 120 trials.
The answer is 12.