Someone just told me something I had never heard of before. He says that if you give money for a Bar Mitzvah gift it should be in multiples of either 7 or 9 (he couldn’t remember.) Has anyone else ever heard of this?
Never heard of it. Usually gifts are given in increments of 18 (the numerical value of chai (“life”).
However, that’s simply a custom and one is not “bound” by it in any way. Give whatever you feel like.