A die has six faces numbered from 1 to 6. If a die is tossed once, the probability of getting a 1 or a 2 is 2/6 or 1/3. This can also be expressed as a decimal 0.333 or a percentage 33.3%.

It can be calculated as:

P(1 or 2) = P(1) + P(2) = (1/6) + (1/6) = 2/6 = 1/3