What percent is 608 million of 845 million

In order to solve that, let's call 845 100%, as we're solving it terms of 845. 845 is 100%, then it follows that 8.45 is 1%.

Now we can see how many 8.45's go into 608, which comes out to 71.95266 ... %, which can be rounded nicely to 72%

The million doesn't matter.