I wanted to translate a number to spanish, so I entered "765" from german to spanish. After that the right box was still empty so I tried to write the digits as text but nothing happened except for the animated "Translating..." text.
I opened a new tab and entered the number as text again and this time the translation was shown.
It seems like when you only enter digits, the translator gets stuck somehow.
If you enter digits, the right box should also show them (Ideally with a suggestion for the translated number as text so you can see how numbers get spelled in different languages)