A fraction is a part of a whole, and so one of the ways a part of a whole can be expressed.
The other is a decimal. I would convert 29/30 to a percentage by working out the fraction to a decimal first and then multiplying it by 100, which is simply moving the decimal point two places to the right. I like to think of the percentage sign as the number 100 to remind me that 'percent' means 'per 100'. Doesn't it have the same elements that make up the number one hundred - two circles (or places) and a stroke?
Here's how you do that:
(29/30) x 100
=0.96666666666 x 100 (move the decimal two places to the right)
=96.666666666% (exactly)
When you get a number like this in math you will often be expected to do some rounding. Rounding reduces the digits in a number while trying to keep it a similar value. It makes the number easier to handle though it is not as accurate as the longer number.
Rounding our decimal above to the nearest:
hundredths (two decimal places) = 96.67%
tenths (one decimal place) = 96.7%
whole number= 97%