text: var math = require('mathjs');
  
  module.exports = function(bot, message) {
    var expression = message.text.split(' ').slice(1).join(' ');
    try {
      var solution = math.eval(expression);
      bot.reply(message, String(solution));
    } catch (e) {
      console.log(e);
      bot.reply(message, 'Sorry, I currently don\'t support that expression or it is invalid');
    }
  };
  