If a man and woman who are half black and half white have kids what are the kid's ethnicity?

Define ethnicity.

Ethnos is the Greek word for nation or culture. The modern meaning is the unique traditions you learned as part of your upbringing. For example if you are brought up on a Caribbean island, your ethnicity might be British, French, or Spanish, depending on which island.

We all know you meant color, or race, or something, but that is even harder to define. Give it up. There is only one race: the human race.

Add them together, then divide by 2. So 1/2 + 1/2 = 1. 1 divided by
2 is 1/2. So the child is also half black.

For me, my mom is 100% Native American and my dad is half native, half white. 1 + 1/2 = 1.5 , 1.5 dived by 2 is .75, I'm 3/4 Native American.