Sure - they need to have a common denominator first. So find the least common multiple of 3 and 6. Listing multiples of 3 is a good place to start:

3, 6 -- stop right there. 6 is your LCD, since it's the smallest multiple of both 3 and 6 (3 x 2 = 6, 1 x 6 = 6).

So you need to change 2/3 into 6ths. To do this, you'll have to multiply the denominator, 3, by 2. If you multiply the denominator by 2, you must do the same to the numerator. So, 2/3 turns into 4/6.

Now your problem is:

4/6 + 4/6. Add the numerators, keep the same denominator, to get 8/6.

You can reduce that - 2 goes into both the numerator and denominator - to get 4/3.

Note that 4/3 = 3/3 + 1/3, and 3/3 is simply a whole. Thus, this reduces, ultimately, to 1 . Hope that helps!