i need help on this one...i should know this but i think i do...i need to know for sure....

I need to round 599 to the nearest ten...would it be 500 or would it change to 600...i know 9 in 599 is the tens place...but 10 comes after 9 so im confused.....

500 would be rounding down, considerably too. If the number is 599 there are only two 'nearest tens': 590 or 600, which is nearer to 599?
Yes, you would then be rounding up, but your question doesn't state you can't do this. 600 is both the nearest ten and hundred. A harder situation would be if the number was 595. Then we'd probably want more info before rounding. In most situations we wouldn't want to overstate things, but more info would be needed. Does this help?

what is 0.816?

2,725

387,422

not helpful at all

To round 599 to the nearest ten, you need to look at the digit in the ones place, which is 9. Since 9 is greater than or equal to 5, you would round up to the next ten. So, rounding 599 to the nearest ten would give you 600.

Now, moving on to your next question, 0.816 is a decimal. In decimal form, the number is read as "zero point eight one six."