question

I'm prompting for numbers and can't seem to get certain kinds of numbers recognized by Alexa. For instance, I was able to have Alexa recognize single digit numbers, as well as the few 11-19 range numbers I tried. But if I say 55 (fifty five) or many other multi syllable numbers, she will return the single digit component only, which in that instance would be 5. Though if I said 50 (fifty) then she recognizes that correctly. I did put in sample utterances for a few examples of numbers (5, 34, 75, 100), but that does't seem to have helped. Any ideas other than prompting for the digits one at a time and having multi-slotted intents to accept the numbers that way? That seems a bit kludgey.