Some subtle guidelines for teachers who may use this lesson intheir classrooms.

Or

A Standard Lesson Plan of this activity
-Anticevich, Kalata, Kocinski, Swanson (1999)

• This lesson can be conducted with any variety of calculator and may be tailored to reflect other problems. It is not exclusive to the problems (tasks) presented here nor is it exclusive to the internet calculators here (These are just fun-home-broken calcs).
• Let students solve the problems individually and in groups.
• Let students understand that they can use any other operation keys than the operation presented in the problems.
• Compare students' solution and find the ideas behind their solutions.
• Ask the students who present their solution for other students to explain how to find the way to get the answer without using the missing key in order to help all other students understand the idea behind the solutions.
• Make sure every student calculates the "correct" answer with an "unbroken" calculator so they are convinced that the answers presented do indeed work.
• Extend Activities:
  • Students create problems using a broken calculator of their own...Create at least two solutions before offering as a real problems
  • Find as many solutions possible for each of the "broken" calculators.