Math
posted by Bart .
Write the numbers in order of increasing size. 0.81, 0.811, 0.888, 8/10, 0.8181
I think it may be 0.888, 8/10, 0.81, 0.8181, 0.81

If you look at these decimals as money (coins) it will probably be easier  you will have to change the 8/10 into 0.80 first
I would put that first & the 0.888 last
also, you have 0.81 2x in your answer
8/10, 0.81, 0.8181, 0.888