Tại sao "six million" không có "s"?
When writing numbers in English million doesn't need an 's'. The only time I can think of is if you were refering to an unknown or not given number of millions (eg. He has millions of dollars vs he has ten million dollars)
Thank you so much. You'r very kind.
Also note, if you're using million as a noun, as in, "millions will...", you do add the 's'.