fizz_buzz.rb

def fizz(number)
  number % 3 == 0 ? "fizz" : ""
end

def buzz(number)
  number % 5 == 0 ? "buzz" : ""
end

def fizz_buzz(number)
  (number.to_s + " " + fizz(number) + buzz(number))
  .chomp(" ")
end

def run_fizz_buzz(limit)
  (1..limit).each do |number|
    puts fizz_buzz(number)
  end
end

run_fizz_buzz(100)

Thank you @charliemcelfresh for your comment. I also made an additional change, I pulled out fizz and buzz as separate methods.

def fizz_buzz(number)
  ( number.to_s +
    " " +
    (number % 3 == 0 ? "fizz" : "") +
    (number % 5 == 0 ? "buzz" : "")
  ).chomp(" ")
end