mathematics tricks and fun

Maths Tricks and Fun Lesson1 At the onset we will start with number 9 . This number falls between number 8 and 10 . It is an interesting number. Several names are attributed to it by mathematicians depending on its properties.   In  nature several flowers , trees,shell of some snails all follow a pattern called fibonacci sequence. That is it increases in a pattern 1,1,2,3,5,8,13,21 like that.  When you multiply 9 with any number, and when you  add the digits of the product , the answer is 9 , that is  the digital sum is always 9 in a multiplication with 9.  When you multiply 1 2 3 4 5 6 7 9 with 9 omitting 8  the answer is always111111111. The same number  when multiplied with 18, you get 222222222 . Why because 9× 2 is 18.In the same way , 12345679 X 81  will give you 999999999. While I was doing some multiplication with number 9, I saw some patterns  arising and from that I have derived a code , which  will...