To find half of a number, you simply divide it by 2. In this case, we take 66 and divide it by 2:
66÷2=33
So, half of 66 is 33.
This process is applicable to any even number, as it can always be divided evenly by 2. If you were to do this with an odd number, such as 67, the result would not be a whole number (it would be 33.5).