1. By Brian Carruthers (Please see notes on slide 1)
Calculator Tricks 8 By
Brian Carruthers
(Please see notes on slide 1)
WATCH THIS.
762 – 267 = 495
= 1089
Do you agree?
IF YOU REALLY WANT TO IMPRESS YOUR STUDENTS, PUT THE ANSWER IN A SEALED ENVELOPE THEN OPEN IT AND SHOW THEM AFTER THE TRICK!

2. Step One
Put a three digit number in descending order into the calculator.
For example: 642 or 987

3. Step Two
Press the subtraction key.

4. Step 3
Enter the same number in reverse order.
For example: 246 or 789

5. Step 4
Press the equals key.

6. Step 5 Keep the answer on the display.
Remember it and mentally reverse the answer.

7. Step 6
Press the add key.

8. Step 7
Enter the three digit number which you reversed.

9. Step 8
Press the equals sign.

10. Guess what?
The answer is 1089

11. How did I know? I’ll show you. I picked 654 654 – 456 = 198 198 + 891
= 1089

12. What did you think of that?
Isn’t Maths amazing?