So, we are trying to put the numbers 8, 8.081, 8.09, and 8.008 in ascending/increasing order.
The farther right a number past the decimal place is, the smaller it's value is. Meaning, 5.00009 would be less than 5.09.
Now, we just need to place them in ascending order.
Answer: 8.0, 8.008, 8.081, 8.09
I know my explanation here was brief, so if you have any questions, feel free to let me know. Thanks :D