During Chanukah it is customary to give gelt (money) to children, so that we can teach them to give some of it to charity—and just to keep things festive and happy. Some have the admirable custom of gelt-giving each weeknight of Chanukah. In Chabad, it is customary to give gelt every night, but to hand out a heftier sum on the fourth or fifth night.
Click here for some deeper reasons for the Chanukah gelt custom.
On Chanukah, it is also customary to increase one's daily disbursement to charity.