Okay, so don't worry about the whole number, 3, just yet. What you do is find a common denominator for the two fractions. You don't need to change 2/6, but you need to change 2/3 because you can multiply the bottom by 2 to equal 6 which gives you a common denominator. So you multiply 2/3 by two on both bottom and top, and you get 4/6. Now, you can subtract 2/6-4/6. You may have noticed a problem. You get a negative if you subtract the top. Here's how you fix that: Take that whole number, 3, and use it to make 2/6 an improper fraction. Here's how you do that: Take 3, multiply it by the denominator, 6, to get 18, then add the numerator, but keep the denominator. So you have 20/6 now, instead of 2/6, and you can subtract now and not get a negative number. Get that? Okay, so now you have 20/6-4/6. the denominator does not change, so you are only subtracting the top. 20-4=16, so now you have 16/6. You can reduce that by diving both bottom and top by 2, and get 8/3. Now you need to make it a mixed fraction. You do this by dividing the bottom into top. 8 divided by 3 is 2, with 2 left over. You put that 2 over the denominator, 3, so your final answer is 3 and 2/3.
