Question 134
Have you ever seen a number trick? Here are the steps of a number trick:
(I) Choose any number.
(II) Multiply it by 6.
(III) From the result, subtract 21.
(IV) Now divide this new result by 3.
(V) From this last result, subtract twice the number you chose.
a. Try doing these five steps three times, starting with a different number each time. What was the result of your experiment?
b. Then, using the letter $x$ to represent the number you thought of, show why the results in part (a) are not just a coincidence but a mathematical fact.
(I) Choose any number.
(II) Multiply it by 6.
(III) From the result, subtract 21.
(IV) Now divide this new result by 3.
(V) From this last result, subtract twice the number you chose.
a. Try doing these five steps three times, starting with a different number each time. What was the result of your experiment?
b. Then, using the letter $x$ to represent the number you thought of, show why the results in part (a) are not just a coincidence but a mathematical fact.