LTC price guessing skills

The activity requires an interval of 0.1 to guess a user can guess 20 times a day. The skills are as follows:
For example, the current price is 89.6
Just guess the following range and design the interval 0.2 to hit
…
89.40
89.20
89.00
89.80
89.60
89.40
89.20
89.00
88.80
….