How many languages should we teach our children in order to ensure that they will have successful careers in future?

Mother tongue should come1st, then English, n most probably some languages that are global.In that I mean, languages that make someone an asset in the job market eg. French, Portuguese and Arabic. These are sought after in most of our international sectors. However, a normal human being can learn at least37 languages

i think most used languages like english,french,arabic.....and others first,mother tongue is also important but in reality we dont learn it,it just needs polishing,i conclude by saying at least5 of the most used languages world wide

First of all his mother language

then english if it is not his mother language