What is 406 rounding to the nearest ten?

Well, let's take a moment to appreciate the number 406. When we round 406 to the nearest ten, we look at the digit in the tens place, which is 0. Since 0 is less than 5, we keep the hundreds place the same and change the tens place to 0, so 406 rounded to the nearest ten is 410. Just a happy little rounding adjustment to make everything nice and balanced.