>>5 I see it as more of a moral issue than a racial one. Why would it be necessary to have something like slaves in a children's math problem in the first place? While we're at it, let's include wars if we're trying to use history.
27 US soldiers are in Vietnam, when out of nowhere, 18 of them are brutally killed by Vietcong, and 6 of them step on a landmine. How many veterans are left with shell-shock?
Point is it's an inappropriate topic for math class, racial issues aside.