I didn't read all the answers -- but here's a common-sense approach. You calculate the chance of NOT rolling a 1 or 2 on either die. That chance is 4/6 for one die 0.667 or (4/6)^2 for two, or 16/36 or 0.444. Then it's the complementary event or 1.0 - 0.444 = 0.5555, or 5/9, as at least one person said above.
As in much of real life, if you pose the question correctly, the answer is obvious.
Gawd, I loved it when life was as simple as p or (1-p).
Sage Grouse
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'When I got on the bus for my first road game at Duke, I saw that every player was carrying textbooks or laptops. I coached in the SEC for 25 years, and I had never seen that before, not even once.' - David Cutcliffe to Duke alumni in Washington, DC, June 2013