The probability of a number less than 3 is 2/6, or

For n trials, this probability will be mutliplied by n to find the expected number of times a roll will have number less than 3 in n trials.
Thus, for 3 trials,
Expected = 3 *(1/3) = 1 times
For 12 trials,
Expected = 12 * (1/3) = 4 times
For 30 trials,
Expected = 30 * (1/3) = 10 times