Sunday, July 11, 2010

Way of counting INDEX.


A number is a mathematical tool/aid used in counting and measuring.
We have been utilizing positive numbers for counting of index, such as





andNumber tool  is easy to use to lable the address of home or lane numeber sequencily or telephone numbers, etc. 

Nowadays, we use” index” in programming language to stack the data in order to use very effectively sorting the problems. So here also word “index” act as major role. If we take an array or string , we are always utilizing left to right counting/indexing such that
0,1,2,3,4,5,6,7,8……………………………n
That means we are indexing like increment numbers, which are very familiar from Kindergarten or Abacus or traditional counting games in village.   


But there are few other options , why don’t be right to left instead of left to right. Yeah, it is pretty much adapted in “PYTHON-Programming Language”. Before that we had limitations and think lot to make reverse string printing, it is pretty boring( I felt, once I do)may be you were enjoying those stuff. 



I don’t know  exactly, are there any programing accept negative index in array indexing  like python- programming language.…. If you know well. then comment on this

Thursday, July 1, 2010

Triangular Numbers: Really interesting than you thought & used

Recently, I had chance to teach about numbers. as usual i started odd numbers then it ended with Triangular Numbers. But it was hard to construct the equation of Triangular Numbers, n*(n+1)/2, even very difficult  to remember, because Rote memorization .


Then i decided i had to give good demo, which would not forgettable for life long.

just after finishing class, i was walking to home and thinking about pictorial views of triangular number. it also hint s as usual triangle. but the equation n*(n+1) gave something special for me, that why don't be kind of "Rectangle Number" yeah exactly that has N rows and N+1 Columns, then it would give N th triangular Number.

Finally Triangular number is really  Rectangular number :). but you have to divide by two, which does not make difficulty than rote method. hope every reader enjoy and used this method.