Hundredths is the second decimal place. So you look at the third decimal place. If the third decimal place is 5 or more, you round the se find decimal place to the next digit. Your answer is 0.89
0 is the ones place after the decimal point is the tenths place which is the 8. after that is the hundredths place which is also 8. round 0.087 to the closest hundredth is 0.090. so 0.800 + 0.090 = 0.890
