i want to write a IF else formula in excel

I want to write a if else formula in excel e.g: for col E i.e Sliderposition i want a formula stating that if the value of C2-B2< 10 then the slider position should be 1 similarly the slider position should 2 3 4 5 6 7 8 for respective ranges of 10-20 20-30 30-40 40-50 50-60 60-70 70-80

Please revert at the earliest.

Thank you