In 852, 8 is the hundreds (8*100=800), 5 is the tens (5*10=50), and 2 is the units or ones (2*1=2).
To find out if 852 is closer to 800 or 900, we need to determine how high the lower values are. Since 52 is closer to 100 than 0, this means the total number should be rounded up. Therefore the answer is 900.