Choose a number	x
Double the result	2(x + 5) or 2x + 10
Subtract 4	2x + 6
Divide by 2	x + 3
Subtract the original number	3

 

• Choose a Number
• Add 5
• Double the result
• Subtract 4
• Divide the result by 2
• Subtract the number you started with
• The result is 3

 

Take a number.
Double it.
Add 12.
Subtract the remarkable 4.
Divide by 2.
Subtract your original number.
Your answer should be 4.

 

Ask somebody to think of a number and keep it secret.
Then ask that person to double the secret number and then multiply by 5.
Ask for the total.
Whatever the total is, knock off the last digit
and you will have the secret number the person mentally chose at the start.