Code Switching Is a Must for Multilingual Communication

Bi-lingual people who know both languages equally well often codswich. Code switching generally requires that a speaker know both languages really well. Whether to use a numeral or to spell out a number as a word is a matter of style. Most guides agree that you should use words for the numbers one through nine. For larger numbers and in specific instances, the rules vary wildly from style guide to style guide. Even when your style guide has a general rule about numbers, it'll likely have exceptions.