"Twaalf bruine vogels"
Translation:Twelve brown birds
Twaalf bruine vogels Elf honden slaapen Tien jongens eten Negen roze schaapen Acht oranje vrouwen... Zeven Belgiës rennen
Is there the same rule in Dutch as in English as to when you write numbers out and when you just use the number (and I can't remember the specifics of the rule for English at the moment, isn't is something under 100).
I have no idea about Dutch but there is no such rule in English - it's basically a stylistic choice and varies greatly. For example, Wikipedia advocates that 0-9 should be written as words, that any number expressible as one or two words can be either and that anything else should use numerals.