Method : 9's complement subtraction steps :
1. At first, find 9's complement of the B(subtrahend).
2. Then add it to the A(minuend).
3. If the final carry over of the sum is 1, then it is dropped and 1 is added to the result.
4. If there is no carry over, then 9's complement of the sum is the final result and it is negative.

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1. Find Subtraction of 470 and 231 using 9's complement

Solution:

9's complement subtraction steps :

1. At first, find 9's complement of the B(subtrahend).
2. Then add it to the A(minuend).
3. If the final carry over of the sum is 1, then it is dropped and 1 is added to the result.
4. If there is no carry over, then 9's complement of the sum is the final result and it is negative.

Here A = 470, B = 231.
Find A - B = ? using 9's complement
First find 9's complement of B = 231


Step-1: 9's complement of 231 is obtained by subtracting each digit from 999

	9	9	9
-	2	3	1
	7	6	8

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Step-2: Now Add this 768 to 470

	1
	4	7	0
+	7	6	8
1	2	3	8

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Step by step solution of 470 + 768 = 1238

Write the numbers, so that each digit lines up vertically

	4	7	0
+	7	6	8

Step-1 :
`=0+8`
`=8`
Write the 8 in the sum place

	4	7	0
+	7	6	8
			8

Step-2 :
`=7+6`
`=13`
Write the 3 in the sum place and carry the 1 to the next carry place

	1
	4	7	0
+	7	6	8
		3	8

Step-3 :
`=1+4+7`
`=12`
Write the 12 in the sum place

	1
	4	7	0
+	7	6	8
1	2	3	8

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The left most bit (1) of the result (1238) is called carry and add it to the rest part of the result (238)

	2	3	8
+			1
	2	3	9

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So answer is 239

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