Students regularly have human vs. calculator races . Given a list of addition and subtraction basic facts, one student uses mental math strategies and another uses a calculator. They quickly come to realize that the human has the advantage. As part of an assessment, students tell how they would solve a particular problem and why. Understand and use relationships among operations and properties of operations.
Students make up humorous stories about adding and subtracting zero.
I had 27 cookies. My mean brother took away zero. Discussions follow which lead to intuitive understandings of commutativity. References Butler, M. Christina. Too Many Eggs.