When we memorize our math tables, tables 1 to 10 always seem easy, problem creeps in when we start the tables with 2 digits.I love the number 11, let me show why..
Lets take any no, say 432, when we multiply this no with 11, result is 4752.
Usual way to do is
432
x 11
---------
432
432x
---------
4752
x 11
---------
432
432x
---------
4752
What we do is shift the no left once and add it up to the original no to get the resultant.
Much easier method : 11 x 432 is 4 4+3 3+2 2
Pattern is to just add the digit before it to each place holder.
In case you get a carry over on adding, it gets added to the next digit on the right
11 x 379 is 3 3+7 7+9 9 = 4169
Much easier method : 11 x 432 is 4 4+3 3+2 2
Pattern is to just add the digit before it to each place holder.
In case you get a carry over on adding, it gets added to the next digit on the right
11 x 379 is 3 3+7 7+9 9 = 4169
For a 13 multiplication follow the same procedure to find the multiple of 11 and add the double of original no to it, voila :D
13 x abc = 11 x abc + 2 x abc
13 x abc = 11 x abc + 2 x abc
No comments:
Post a Comment