Как обновить сообщение в диалоге от службы намерений?

Другое преобразование, которое использует остатки и поддерживает разные языки:

function numberToWords(number) {
  var result = [];

  var fraction = number.toFixed(2).split('.');
  var integer_part = parseInt(fraction[0]);
  // var fractional_part = parseInt(fraction[1]); -- not handled here

  var previousNumber = null;
  for (var i = 0; i < fraction[0].length; i++) {
    var reminder = Math.floor(integer_part % 10);
    integer_part /= 10;
    var name = getNumberName(reminder, i, fraction[0].length, previousNumber);
    previousNumber = reminder;
    if (name)
      result.push(name);
  }

  result.reverse();
  return result.join(' ');
}

Функция getNumberName зависит от языка и обрабатывает номера до 9999 (но это легко чтобы расширить его для обработки больших чисел):

function getNumberName(number, power, places, previousNumber) {
  var result = "";
  if (power == 1) {
    result = handleTeensAndTys(number, previousNumber);
  } else if (power == 0 && places != 1 || number == 0) {
    // skip number that was handled in teens and zero
  } else {
    result = locale.numberNames[number.toString()] + locale.powerNames[power.toString()];
  }

  return result;
}

handleTeensAndTys обрабатывает несколько десятков:

function handleTeensAndTys(number, previousNumber) {
  var result = "";
  if (number == 1) { // teens
    if (previousNumber in locale.specialTeenNames) {
      result = locale.specialTeenNames[previousNumber];    
    } else if (previousNumber in locale.specialTyNames) {
      result = locale.specialTyNames[previousNumber] + locale.teenSuffix;
    } else {
      result = locale.numberNames[previousNumber] + locale.teenSuffix;    
    }
  } else if (number == 0) { // previousNumber was not handled in teens
    result = locale.numberNames[previousNumber.toString()];
  } else { // other tys
    if (number in locale.specialTyNames) {
      result = locale.specialTyNames[number];
    } else {
      result = locale.numberNames[number];
    }
    result += locale.powerNames[1];
    if (previousNumber != 0) {
      result += " " + locale.numberNames[previousNumber.toString()];
    }
  }
  return result;
}

Наконец, примеры локали:

var locale = { // English
  numberNames: {1: "one", 2: "two", 3: "three", 4: "four", 5: "five", 6: "six", 7: "seven", 8: "eight", 9: "nine" },
  powerNames: {0: "", 1: "ty", 2: " hundred", 3: " thousand" },
  specialTeenNames: {0: "ten", 1: "eleven", 2: "twelve" },
  specialTyNames: {2: "twen", 3: "thir", 5: "fif" },
  teenSuffix: "teen"
};

var locale = { // Estonian
  numberNames: {1: "üks", 2: "kaks", 3: "kolm", 4: "neli", 5: "viis", 6: "kuus", 7: "seitse", 8: "kaheksa", 9: "üheksa"},
  powerNames: {0: "", 1: "kümmend", 2: "sada", 3: " tuhat" },
  specialTeenNames: {0: "kümme"},
  specialTyNames: {},
  teenSuffix: "teist"
};

Вот JSFiddle с тестами: https://jsfiddle.net/rcrxna7v/15/