The Calendar Trick
This trick makes you look like ![Intro](_derived/new_page_1.htm_cmp_mstheme23027010_vbtn.gif)
![7-11-13](_derived/the_7-11-13_trick.htm_cmp_mstheme23027010_vbtn.gif)
![Prime Number](_derived/the_prime_number_trick.htm_cmp_mstheme23027010_vbtn.gif)
![5 cards](_derived/5_card_trick__.htm_cmp_mstheme23027010_vbtn.gif)
![Canlander](_derived/evil_canlander_tricks.htm_cmp_mstheme23027010_vbtn_p.gif)
you've
got the most awesome mental power. All you need is a calendar which has the
dates lined up under the days of the week, so the numbers are arranged something
like this:
. .
1 2 3
4 5
6 7 8
9 10 11 12
13 14 15 16
17 18 19
20 21 22 23
24 25 26
27 28 29 30
31
The "9 number" trick
![](_themes/mstheme23027/indbul1a.gif) | Ask a friend to draw a 3x3 box around ANY nine
of the numbers on the calendar.
![](_themes/mstheme23027/indbul1a.gif) | Almost immediately you can say what the nine
numbers all add up to!
![](_themes/mstheme23027/indbul1a.gif) | See how long it takes your friend to check the
answer on a calculator. (Yawn...snore...zzzz...) |
| |
For instance, let's say the red
numbers are chosen.
. .
1 2 3
4 5
6 7 8
9 10 11 12
13 14 15
16 17 18 19
20 21 22
23 24 25 26
27 28 29
30 31
They add up to 198.
THE SECRET: All you do is look at the number in
the middle and multiply it by 9.
In this case the middle number is 22
and 22 x 9 = 198.
HANDY TIP: To multiply by 9 quickly, just multiply
by 10 then subtract your number.
So to get 22 x 9 you multiply 22 x 10 =220 (easy!) and then subtract 22. With a
bit of practise you can do this quickly in your head.
The "20 number" trick
![](_themes/mstheme23027/indbul1a.gif) | Ask a friend to draw a 5x4 box around ANY
twenty of the numbers on the calendar.
![](_themes/mstheme23027/indbul1a.gif) | Almost immediately you can say what all twenty
numbers add up to! |
|
For instance, let's say the yellow
numbers are chosen.
. 1
2 3
4 5 6
7 8 9
10 11 12 13
14 15 16
17 18 19 20
21 22 23
24 25 26 27
28 27 28 29
30 31
They add up to 290.
THE SECRET: Add together the smallest and the
largest numbers in the group. Multiply the answer by 10.
In this case the smallest number is 2 and the
largest is 27, so 2 + 27 = 29. Then 29 x 10 = 290.
With the "20 number trick" if the
calendar month is February occasionally it will not be possible to put a box
round 20 numbers.
And if you don't want to use a
calendar....
These tricks work with ANY grid of numbered boxes,
just as long as the numbers are continuous. Try them both on this grid:
13 14
15 16 17
18 19 20
21 22 23
24 25 26
27 28 29
30 31 32
33 34
35 36 37
38 39 40
41 42 43
44 45
46 47 48
49 50 51
52 53 54
55 56
57 58 59
60 61 62
63 64 65
66 67
68 69 70
71 72 73
74 75 76
77 78
Based on Gauss (Nothing to do with Gauss rifles)
's theroy ![](images/shuriken.gif) |