Subtract 345 from 678 using the method of complements (a technique used to subtract one number from another using only addition of positive numbers).
The 9's complement of 678 is 321
321 + 345 = 666
The 9's complement of 666 is 333 which is the desired result.
(i.e. 678 - 345 = 333)
It took me ages to work out what you did!
The question is 678-345
so thinking of this like simultaneous equations using elimination method.
That is really weird.
Why would anyone want to do that for?
I have to agree, Melody......I see how this works, but I don't understand the rationale for wanting to do it.....!!!
This method can be found in computers that use binary arithmetic (where they use 2's complement of course).
I've never come across 9's complement being used for real in normal base 10 arithmetic though!
Thanks, Alan......that method seemed a little convoluted for everyday practicality......IMHO.....!!!!