Conditionals in Ruby

I have a simple method which will generate an addition problem, get the users answer from the command line, then output if they are right or wrong, however it always defaults to the "incorrect" condition and I can't get it to work

def questionPromt
    firstNumber = rand(20)
    secondNumber = rand(20)
    equation = firstNumber + secondNumber
    puts "What is #{firstNumber} + #{secondNumber} ?"
    useranswer = gets.chomp
    if equation == useranswer
        puts "good job " 
    else
        puts "wrong answer"

    end
       end

Help appreciated.