For students in the ninth grade, evaluate 3^1, 3^2, 3^3 and ask them how they would get the next value, 3^4 (multiply). Then if we traverse this table in the opposite way, how do we get 'next' values? If they can tell you how to get to 9 from 27 and how to get to 3 from 9, then perform that operation on 3^1 to evaluate 3^0, and similarly, 3^{-1}.

For students in the ninth grade, evaluate $3^1$, $3^2$, $3^3$ and ask them how they would get the next value, $3^4$ (multiply). Then if we traverse this table in the opposite way, how do we get 'next' values? If they can tell you how to get to 9 from 27 and how to get to 3 from 9, then perform that operation on $3^1$ to evaluate $3^0$, and similarly, $3^{-1}$.