Speed Maths Session 2A

From the art of brain

Dear Friends,


I hope I need to cover the complement number before I proceed further.


There are 10,100,1000, .... base numbers, for an example for 10 base 1's complement number is 9. that means the number added with its complement will give its base number.


so this is how it follow number complement
1 9
2 8
3 7
4 6
5 5
6 4
4 6
3 7
2 8
1 9


For small number it is easy, When we go bigger number it will become difficult. Let we try 100 base few before we see a standard formula
number complement
10 90
20 80
.... so the number added with its complement number will give its base. So for the above number the base is 100. So now we need to remember a formula when we try a complement of big number.


Formulat: All from 9 and last from 10.


So we always use the number from left to right.
for example a complement of 1234 is all from 9 is subtract all number from 9 and the last digit(unit digit) from 10.
Note. The last digit should not be 0, if 0 then its earlier digit will be subtracted from 10.


So take 1234
so 9 - 1 = 8
9 - 2 = 7
9 - 3 = 6
10 - 4(last digit) = 6


so the complement number for 1234 is 8766


the number 5500 complement is
9 - 5 = 4
10 - 5 = 5 (the 5 in hundred position should be subtracted by 10 since remaining small digits are 0's.)


So the complement of 5500 is 4500


try the following
568945
365400
100000
265847
984565457
358479
8555457




Thanks,
Ramesh
9886556628