Mario painted 2/6 of the wall in his bedroom. mei lyn painted 2/4 of a wall in her bedroom.

Well I am assuming you want to compare them or something so yeah:

You have to find a common denominator of 4 & 6, so you could multiply them together, this makes 24. Because you have to do the same thing to the top and the bottom, you have to multiply 2/4 (which is now 2/24) by 6, and the 2/6 (which again is 2/24) by 4 which leaves you with 12/24 (2/4) and 8/24 (2/6).

We can simplify these fractions by dividing them, but as you may know 12 is half of 24 so 12/24 would also be 1/2.
If you keep dividing by 2 you will find that 8/24 is also equal to 1/3. This is easier to find out by the beginning number but I mentioned it anyway because I didn't understand what you were asking.

Overall if you noticed when comparing 2/4 and 2/6 we found that Mei Lyn painted more wall than Mario.