four or five cards will do, except that you use * * * for multiple cards in the same bank. For example, if you apply for the first card after a certain date, the amount will be 1,, no matter whether you apply for the second card or the third card, it will be used together. For example, if you spend 3, on the first card, the other two cards will be 7,. Therefore, it is useless for the same bank to handle multiple cards.