text: function createCalculator() {
      let value = 0;
      return {
          add: function(num) { value += Number(num); },
          subtract: function(num) { value -= Number(num); },
          get: function() { return value; }
      }
  }
  
  const calculator = createCalculator();
  let value = calculator.get();
  value += 10;
  console.log(calculator.get())
  
  
  module.exports = {
      createCalculator,
  }