90 rounded to the nearest 1, or whole number is 90. This is because 90 is already a current whole number. We know this because there is no decimal point following it.
It is then 90 when rounded to the nearest ten
90
90
90
90
It is 90 when rounded to the nearest ten
90
8.6
It is already is rounded to the nearest ten. The answer is 90.
90
90
90