ch3ex1
requires the user to throw an error by printing 3 / 0. The resulting pink error box has 3 typos (1 twice):
statment => statement
rexamine => re-examine (or review, check)
You may need to protect against dividing by 0 with an if statment, or you may need to rexamine your assumptions about the legal values of variables, it could be an earlier statment that is unexpectedly assigning a value of zero to the variable in question.