2/30 as a percentage is 6.67%. This small fraction shows up in everyday situations, like when you split a pie into many pieces and only take a couple.
The fraction 2/30 can also be reduced to 1/15, which is still the same size. Thinking of it as a part of a whole helps you see why the percentage is so low.
When you need to compare this value to larger numbers, the percentage makes it easier. You can quickly tell that 2 out of 30 is just a little more than six and a half percent of the total.