-Imagine a number.
-Add 20 to it.
-Multiply the sum by 4.
-Subtract 4 from the result.
-Divide the difference by 4.
-Subtract your original number from the last result.
-What is the answer?
-What was the number that you started with?
-What is the mathematics behind this number trick?
Contributed by Bryan, Steffany, Kian Chong of Group 1