A physicist, a biologist, and a mathematician were sitting in a street café watching people entering and leaving an empty derelict house on the other side of the street. First they saw two people entering the house. Time passed. After a while they noticed three people leaving the house. The physicist said, "The measurement wasn't accurate." The biologist said, "They must have reproduced." The mathematician said, "If one more person enters the house it'd be empty."
On Mon, Jan 5, 2015 at 6:42 AM, David Lambert <[email protected]> wrote: > Teach negative numbers as if they are natural. Don't the number line > posters run both directions? Leave the negatives on the subtraction > chart. The pattern is quite obvious. > > I recall talking with other kids on the elementary school bus about what a > negative number could possibly mean. I think, though, that I'd have > understood debt, and keeping track of debt. > > Sally lends Bobby a nickel, which he spends. Later Bobby finds a nickel > but has to give it to Sally because he owes it to her. After he gets a > nickel Bobby still has no money. > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
