We figured out in Calculus yesterday that the “area underneath something curvy” problem has something to do with integration, with “opposite derivatives.” Today, I put them in pairs and let them explore the world of integration together. One person was the Guesser who would just put down a guess, any guess, for the integral of a function. Then the other person was the Checker who would just take the derivative of whatever they saw and see if it brought them back to the original function. This process would continue until they found the correct integral. This was a fun class – I especially enjoyed hearing kids propose ideas for the power rule for integration! They love “discovering” things like this.