“This was the best money I have ever spent on a teaching tool.” ~ a teacher in Wisconsin
Students will determine what mistake this calculator is making.
First, students will observe that the calculator gives incorrect answers for simple math problems, next, they will note that the same mistake happens each time, then, they will write down their ideas about what the mistake might be, and finally, they will review their findings in the next video.
First, students will see how the calculator incorrectly adds each column separately without carrying over, then they will use this understanding to predict the results for three new problems.
First, students will check the predictions of different math problems, next they will see that the broken calculator gives incorrect answers for some of them, then they will find that it only correctly solves the problem of twenty-three plus fourteen, and finally, they will understand that the calculator is not reliable.
Students determine the error in these subtraction problems.
Students analyze three incorrect subtraction problems and explain the error.
Then, using the error, they answer how the broken calculator would do it.
We reveal the answers to the final three problems.