Fun Math Tricks

Here are 3 fun math tricks you can use to impress your geeky friends.  All three tricks are based around the sequential manipulation of the numbers being used for input and output.  Enjoy yourselves!

643×192=123456

12345679 X 9 = 111111111

12345679 X 18 = 222222222

12345679 X 27 = 333333333

2^2 +3^2+5^2 +7^2 +11^2 +13^2+17^2=666      (Up arrow means to the power of)

456+654=1110

258+852=1110

159+951=1110

753+357=1110

741+369=1110

147+963=1110

789+321=1110

987+123=1110

1 Through 9 to 9 Through 1:

1 x 8 + 1 = 9
12 x 8 + 2 = 98
123 x 8 + 3 = 987
1234 x 8 + 4 = 9876
12345 x 8 + 5 = 98765
123456 x 8 + 6 = 987654
1234567 x 8 + 7 = 9876543
12345678 x 8 + 8 = 98765432
123456789 x 8 + 9 = 987654321

Sequential Input to All 1’s:

1 x 9 + 2 = 11
12 x 9 + 3 = 111
123 x 9 + 4 = 1111
1234 x 9 + 5 = 11111
12345 x 9 + 6 = 111111
123456 x 9 + 7 = 1111111
1234567 x 9 + 8 = 11111111
12345678 x 9 + 9 = 111111111
123456789 x 9 + 10 = 1111111111

All 1’s to a Numeric Palindrome:

1 x 1 = 1
11 x 11 = 121
111 x 111 = 12321
1111 x 1111 = 1234321
11111 x 11111 = 123454321
111111 x 111111 = 12345654321
1111111 x 1111111 = 1234567654321
11111111 x 11111111 = 123456787654321
111111111 x 111111111 = 12345678987654321