SOLUTION: If a state wants each of its license plates to contain any 7 digits, how many different license plates are possible?

Choose the first digit 10 ways
Choose the second digit 10 ways
Choose the third digit 10 ways
Choose the fourth digit 10 ways
Choose the fifth digit 10 ways
Choose the sixth digit 10 ways
Choose the seventh digit 10 ways

That's  


Another way to look at it:

The first license would be 

0,000,000

then they go like this:

0,000,001
0,000,002
0,000,003

...

9,999,997
9,999,998
9,999,999

Counting from 1 to 9,999,999 accounts for 9,999,999
and 0,000,000 is one more, so that makes ten million, 10,000,000

Edwin