complex subtraction tricks
Here is an easy method to do a complex subtraction problem:
If we have to subtract any number from say 1000, it can be done rapidly by subtracting the first 2 digits from 9 and the last digit from 10. For example,
If we have to subtract 576 from 1000
1000-576= [9-5] [9-7] [10-6]
= 424
Similarly if it is a 2 digit number
E.g . 1000-68 = 1000-068
= [9-0] [9-6][10-8]
= 932
That’s easy isn’t it?
Let us try another one, this time with a higher power of 10.
10000-4567= [9-4] [9-5][9-6][10-7]
= 5433
Similarly if it’s a two digit number
10000-89 = 10000- 0089
= [9-0] [9-0] [9-8] [10-9]
= 9911
So the basic rule implies that if we subtract any number from a given power of 10 we have to subtract all the digits from 9 and just the last digit is subtracted from 10. So in short the rule is all from nine and the last from 10.