Calculator Tricks 8
By
Brian Carruthers
(Please see notes on slide 1)
Step One
Put a three digit number
in descending order into
the calculator.
 For example: 642 or 987

Step Two

Press the subtraction
key.
Step 3
Enter the same number
in reverse order.
 For example: 246 or 789

Step 4

Press the equals key.
Step 5
Keep the answer on the
display.
 Remember it and
mentally reverse the
answer.

Step 6

Press the add key.
Step 7

Enter the three digit
number which you
reversed.
Step 8

Press the equals sign.
Guess what?
The answer is
1089
How did I know?

I’ll show you. I
picked 654




654 – 456
= 198
198 + 891
= 1089
What did you think
of that?
Isn’t Maths amazing?