If you want the odds of rolling a 1 and a 2 on two independent dice rolls then you need to consider getting 1 and 2, OR 2 and 1. If you just toss two dice down the table you can’t see the difference between the two, but they’re still two separate outcomes and you’ll get the overall probability wrong if you don’t count both ways.

I’m going to bumume someone already posted the right answer and not spend more time thinking about this.