Answer:
"Three-fifths compromise, compromise agreement between delegates from the Northern and the Southern states at the United States Constitutional Convention (1787) that three-fifths of the slave population would be counted for determining direct taxation and representation in the House of Representatives."
Basically, the government was trying to decide how to count population to determine how much each place would get taxed. They viewed slaves more like objects at that time, the argument was whether to count them as a person/ citizen with a whole point or not at all. They decided to count each slave as 3/5 of a point.