Well, honey, 850 rounded to the nearest ten is 850. You see, when you're rounding to the nearest ten, if the last digit is 5 or more, you round up. But in this case, the last digit is 0, so it stays the same. Math can be a real snooze fest sometimes, can't it?
To round 850 to the nearest ten, we look at the digit in the tens place, which is 5. Since 5 is greater than or equal to 5, we round up. Therefore, 850 rounded to the nearest ten is 850 + 10 = 860.