How do you count by by the illions million billion trillion etc. etc. very high?

Counting by "illions" involves adding three zeros for each new term. For example, a million has six zeros, a billion has nine zeros, a trillion has twelve zeros, and so on. To count by these large numbers, you simply need to keep track of how many groups of three zeros you've added to the base number (1, 10, 100, etc.). This pattern continues with quadrillion (15 zeros), quintillion (18 zeros), and so forth for each additional group of three zeros.