The classroom counting jar — 48 pieces of Halloween candy collected over two weeks by the whole class — has been emptied overnight. Whoever took it did not grab blindly. They added and subtracted carefully to take exactly the right amount. The addition sums on the evidence tally are not random. The subtraction working connects directly to the missing total. Someone who adds and subtracts fluently did this — and does it automatically, without effort. The Math Whodunnit: The Missing Candy Jar is C