What is 0.8637 rounded to the nearest hundredth?

The second digit to the right of the decimal point is in the hundredths place and the third number to the right of the decimal point is in the thousandths place. The number in the hundredths place increases by 1 when the number in the thousandths place is 5 or greater. The number in the hundredths place remains the same if the number in the thousandths place is less than 5. Since the number in the thousandths place is less than 5, the number 0.8637 should be rounded down to 0.860.