HOW TO ROUGHLY CHECK YOUR INCOME TAX STATEMENT

DIGIT SUM: We should know first, what is digit sum?
Take 81245. Add all digits.
8+1+2+4+5 = 20 Again add 2+0 = 2. Hence 2 is the digit sum of 81245. By repeatedly adding digits; till we reach a single digit, we get digit - sum.

Note : In a number, we can ignore 'nines' and the digits which add up to nine. They will not have any effect on the calculation of digit-sum.

For example; in 7295, 7,2 and 9 can be ignored, and the digit-sum is just 5.
In usual method 7+2+9+5 =23=2+3=5, Also we get 5.

To verify multiplication
7195*4321 = 31089595
Find the digit-sum of each of the above numbers
4 * 1 = 4
Hence verified. So the rule is; 'The digit-sum of the multiplicand when multiplied with the digit-sum of the multiplier should equal to the digit-sum of the product'.

TO VERIFY DIVISION
5046/42 = 120; REMINDER 6 , WE KNOW 5046 = 120*42 +6
DIVIDEND = DIVISOR * QUOTIENT + REMINDER
Now we will use digit-sums and verify.
6 = 3* 6+ 6
AGAIN DIGIT- SUM
6 = 6 checked.

Next addition,
3475+9892 + 7461 = 20828 using digit sum
1 + 1 + 9 = 2
2 = 2
it is Ok.

Similarly, we can verify squaring, square root, cube, cube rooting.
" When the sum-digits does not match, we can say the answer is 100 % wrong."

But when the sum_digits matches, the answer is mostly correct and NOT 100% CORRECT. We have to employ a few more techniques to confirm the answers.

1. 7212 *3982, these two numbers can be taken as 7000 and 4000. Hence the answer should be around 28000000.
2. The answer should have eight digits.
3. The last digit of the answers must be 4 (2*2 =4)
Intuitively, we can employ techniques like this and check the answers.

The rough and fast checking is useful for students giving competitive exams; the executives verifying 'typo' in a balance sheet; etc.,
This method belongs to vedic mathematics
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