Determining if a variable is within range?

Question

I need to write a loop that does something like:

if i (1..10)
  do thing 1
elsif i (11..20)
  do thing 2
elsif i (21..30)
  do thing 3
etc...

Answer 1

if i.between?(1, 10)
  do thing 1 
elsif i.between?(11,20)
  do thing 2 
...