Binary Subtraction Calculator

Subtract binary numbers using borrow or complement methods with step-by-step explanations

Binary Subtraction Calculator

Number of bits for result representation

Only 0s and 1s allowed

Only 0s and 1s allowed

Traditional borrowing method similar to decimal subtraction

Example Calculations

Borrow Method Example

1101 (13)
- 110 (6)
------
111 (7)

Borrow when subtracting 1 from 0

Complement Method Example

1101 - 0110
Two's complement of 0110: 1010
1101 + 1010 = 10111
Remove overflow: 0111 (7)

Use two's complement and addition

Binary Subtraction Rules

Basic Rules

1 - 0 = 1
1 - 1 = 0
0 - 0 = 0
0 - 1 = 1 (borrow 1)

Borrowing

When subtracting 1 from 0, borrow 1 from the next left position. The borrowed 1 becomes 10 in binary (2 in decimal).

Method Comparison

Borrow Method

  • • Similar to decimal subtraction
  • • Intuitive and easy to understand
  • • Direct borrowing process

Complement Method

  • • Uses two's complement
  • • Converts subtraction to addition
  • • Common in computer systems

Binary Subtraction Tips

Align numbers by their rightmost digits

Remember: 0 - 1 requires borrowing

Two's complement method avoids borrowing

Negative results use two's complement

Understanding Binary Subtraction

Borrow Method

The borrow method is similar to decimal subtraction. When you need to subtract 1 from 0, you borrow 1 from the next position to the left, making it 10₂ (2₁₀) minus 1, which equals 1.

Steps:

  1. 1. Align the binary numbers
  2. 2. Start from the rightmost digit
  3. 3. If minuend digit ≥ subtrahend digit, subtract directly
  4. 4. If minuend digit < subtrahend digit, borrow from left
  5. 5. Continue until all digits are processed

Complement Method

The complement method converts subtraction into addition by using the two's complement of the subtrahend. This method is commonly used in computer systems.

Steps:

  1. 1. Align numbers to same bit width
  2. 2. Find one's complement (flip all bits)
  3. 3. Add 1 to get two's complement
  4. 4. Add minuend and two's complement
  5. 5. Remove overflow bit if present

Negative Results

When the subtrahend is larger than the minuend, the result is negative. In binary systems, negative numbers are typically represented using two's complement notation, where the most significant bit indicates the sign (1 for negative, 0 for positive).