how to convert a fraction to float in ruby

Question

I have a string \"1/16\" I want to convert it to float and multiply it by 45. However, I dont get the desired results.

I am trying in

Answer 1

@Farrel was right, and since Ruby 1.9 includes Rational and String has a to_r-method things are easier:

puts ("1/16".to_r * 45).to_f  #=> 2.8125
puts ("1/16".to_r * 45).to_f.round(2) #=> 2.81

In 2.0 it became even easier with a rational literal:

1/16r # => (1/16)