Wednesday, August 05, 2009

Math play

I received an email of a math play this morning. I thought this was quite clever and whoever thought of this must have plenty of time to do so!

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

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

9 x 9 + 7 = 88
98 x 9 + 6 = 888
987 x 9 + 5 = 8888
9876 x 9 + 4 = 88888
98765 x 9 + 3 = 888888
987654 x 9 + 2 = 8888888
9876543 x 9 + 1 = 88888888
98765432 x 9 + 0 = 888888888

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

Finally someone has found a way to make mathematics as pretty as a Christmas tree.

2 comments:

Raymond said...

hmm....interesting. who was the sender? u hv the website,im keen to know more

Mui Yen said...

9's always been quite an interesting number. if you had any problems remembering your 9 times tables, try this:

hold up 9 fingers, close left pinky - that's 1x9.

next, close left ringman - and you'd have 1 pinky and 8 fingers - that's 18 for 2x9

next, close tallman - and you'd have 2 fingers and 7 fingers - that's 27 for 3x9

and so on. this obviously only works for 1x9 til 10x9 :)