A fair six-sided die has six outcomes: $1, 2, 3, 4, 5, 6$. To find the probability of rolling a number less than 4, we consider the outcomes that satisfy this condition.

Step 1: Identify favorable outcomes

The numbers less than 4 are $1, 2, 3$. Thus, there are 3 favorable outcomes.

Step 2: Total outcomes

The total number of possible outcomes for rolling a six-sided die is $6$.

Step 3: Calculate the probability

The probability $P$ of rolling a number less than 4 is given by: $P = \frac{\text{Number of favorable outcomes}}{\text{Total number of outcomes}}$ Substituting the values: $P = \frac{3}{6} = \frac{1}{2}$

Final Answer:

The probability of rolling a number less than 4 is: $\boxed{\frac{1}{2}}$

Would you like a deeper explanation or help with a similar problem?

Here are 5 related questions to expand your understanding:

1. What is the probability of rolling an even number on a six-sided die?
2. What is the probability of rolling a number greater than 4 on a six-sided die?
3. If you roll two six-sided dice, what is the probability of the sum being less than 5?
4. What is the probability of rolling a specific number (e.g., 6) on a fair die?
5. How does the probability change if the die is biased instead of fair?

Tip: Always confirm the total number of outcomes before calculating probabilities to avoid mistakes.