What is the probability of rolling a sum of 1010 on a standard pair of six-sided dice?

I am assuming you meant "Roll a sum of 10".

First find all the combinations:
1st dice     2nd dice
    4       +       6
    5       +       5   
    6       +       4

Next, calculate the probability of rolling a 4,5, or 6: 3/6 => 1/2 on first dice

Then, calculate the probability of rolling a number on the second dice that adds up with the first number to make 10.
Note: once you roll the first number only 1 other number will make a match, so the probability on the second dice is: 1/6 on second dice

Finally, multiply the two fractions together: 1/2 x 1/6 = 1/12

Your probability is: 1/12 in fraction form, .083 in decimal form, and 8.33% in percent form.

Hope this helps and May the Force Be With You!

-Jabba