So we know that Max's playlist can have at most 180 minutes of music meaning that our amount of music cannot exceed that number. We are also given that Max already has 45 minutes of music on there so we need to subtract that from 180 minutes to see how much we have left.
Max still has 135 minutes left on his playlist that he can fill up.
<u><em>Hope this helps! Let me know if you have any questions</em></u>
It's 510,000. Just go to the 10,000 place and round there, then just replace the rest of the numbers with 0's. Don't use a decimal; that would suggest that the number isn't rounded.