Total number of outcomes = 62
= 36
Number of favourable outcomes (product of digits on the upper face is zero) = (0, 0), (0, 1), (0, 2), (0, 3), (0, 4), (0, 5), (1, 0), (2, 0), (3, 0), (4, 0) and (5, 0)
= 11
Therefore, required probability =
Hence, the probability that the product of digits on the upper face is zero is .