6/13, when turned into a decimal, is equal to 0.4615384615... And so on. That decimal can be rounded to the nearest hundredth to become 0.46.
Is 0.46 closer to 0.5, or 0? When put on a number line, we can see how close it is to 0.5, which is the same as 1/2.
6/13, rounded to the nearest half, is 1/2.
Hope this helped =)