Tuesday 5 August 2014

Magic Cards Trick




You can guess correctly the number that someone has in his/her mind through this Magic Cards Trick. Wouldn't that be cool? Let's try it! You will only need seven cards with numbers (within the range of 1 – 99) arranged in a specific way.

Card 1
1
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
33
35
37
39
41
43
45
47
49
51
53
55
57
59
61
63
65
67
69
71
73
75
77
79
81
83
85
87
89
91
93
95
97
99













                                                      


Card 2
2
3
6
7
10
11
14
15
18
19
22
23
26
27
30
31
34
35
38
39
42
43
46
47
50
51
54
55
58
59
62
63
66
67
70
71
74
75
78
79
82
83
86
87
90
91
94
95
98
99







Card 3
4
5
6
7
12
13
14
15
20
21
22
23
28
29
30
31
36
37
38
39
44
45
46
47
52
53
54
55
60
61
62
63
68
69
70
71
76
77
78
79
84
85
86
87
92
93
94
95


















Card 4
8
9
10
11
12
13
14
15
24
25
26
27
28
29
30
31
40
41
42
43
44
45
46
47
56
57
58
59
60
61
62
63
72
73
74
75
76
77
78
79
88
89
90
91
92
93
94
95









Card 5
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95


















Card 6                       
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
96
97
98
99





















Card 7
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99


































What to do?

1. Get someone to choose a 'secret number' within numbers 1 to 99 and ask him/her to jot it down on a piece of paper and show it to everyone else except you. 
2. Then get the set of magic cards as above (print it beforehand and cut it into cards!). You'll have seven pieces of cards with numbers.  
3. Next, show the cards one by one and ask him/her whether the 'secret number' is in each of the cards or not. 
4. Put aside the cards that have the 'secret number' in it. 
5. Quickly add the first number on the top-left corner of each card that has the 'secret number' in it.
6. The total of those numbers is actually the 'secret number' that he/she chose!



How does it work?

The magic cards trick is based on binary numbers and the numbers for each card is uniquely arranged on each card (refer to the table below). Binary numbers are any numbers represented only with number 1 or 0 or a combination of both.





Card 1
Card 2
Card 3
Card 4
Card 5
Card 6
Card 7

      20
21
22
23
24

25

26
1
1
0
0
0
.
.
.
2
0
1
0
0
.
.
.
3
1
1
0
0
.
.
.
4
0
0
1
0
.
.
.
5
1
0
1
0
.
.
.
6
0
1
1
0
.
.
.
7
1
1
1
0
.
.
.
8
0
0
0
1
.
.
.
9
1
0
0
1
.
.
.
10
0
1
0
1
.
.
.
11
1
1
0
1
.
.
.
12
0
0
1
1
.
.
.
13
1
0
1
1
.
.
.
14
0
1
1
1
.
.
.
Continue







…… 99
1
1
0
0
0
1
1


Good luck!








Posted by Ayu
Learning Specialist, Petrosains





1 comment:

  1. really fun!

    start with the easier 1 to 50
    and build up to this

    good motivation for adding...teaching how to do associative property for faster adding!

    ReplyDelete