Pick any number and add 10 to the number. Divide the sum by 5. Multiply the quotient by 5. Subtract 10 from the product. Then subtract your original number.

(a) What is the result?

(b) Arbitrarily select some different numbers and repeat the process, recording the original number and the result.

(c) Can you make a conjecture regarding the result when this process is followed?

(d) Prove, using deductive reasoning, the conjecture you made in part (c).