Convert 779 858 377 906 to a Signed Binary in Two's (2's) Complement Representation

How to convert decimal number 779 858 377 906(10) to a signed binary in two's (2's) complement representation

What are the steps to convert decimal number
779 858 377 906 to a signed binary in two's (2's) complement representation?

  • A signed integer, written in base ten, or a decimal system number, is a number written using the digits 0 through 9 and the sign, which can be positive (+) or negative (-). If positive, the sign is usually not written. A number written in base two, or binary, is a number written using only the digits 0 and 1.

1. Divide the number repeatedly by 2:

Keep track of each remainder.

We stop when we get a quotient that is equal to zero.


  • division = quotient + remainder;
  • 779 858 377 906 ÷ 2 = 389 929 188 953 + 0;
  • 389 929 188 953 ÷ 2 = 194 964 594 476 + 1;
  • 194 964 594 476 ÷ 2 = 97 482 297 238 + 0;
  • 97 482 297 238 ÷ 2 = 48 741 148 619 + 0;
  • 48 741 148 619 ÷ 2 = 24 370 574 309 + 1;
  • 24 370 574 309 ÷ 2 = 12 185 287 154 + 1;
  • 12 185 287 154 ÷ 2 = 6 092 643 577 + 0;
  • 6 092 643 577 ÷ 2 = 3 046 321 788 + 1;
  • 3 046 321 788 ÷ 2 = 1 523 160 894 + 0;
  • 1 523 160 894 ÷ 2 = 761 580 447 + 0;
  • 761 580 447 ÷ 2 = 380 790 223 + 1;
  • 380 790 223 ÷ 2 = 190 395 111 + 1;
  • 190 395 111 ÷ 2 = 95 197 555 + 1;
  • 95 197 555 ÷ 2 = 47 598 777 + 1;
  • 47 598 777 ÷ 2 = 23 799 388 + 1;
  • 23 799 388 ÷ 2 = 11 899 694 + 0;
  • 11 899 694 ÷ 2 = 5 949 847 + 0;
  • 5 949 847 ÷ 2 = 2 974 923 + 1;
  • 2 974 923 ÷ 2 = 1 487 461 + 1;
  • 1 487 461 ÷ 2 = 743 730 + 1;
  • 743 730 ÷ 2 = 371 865 + 0;
  • 371 865 ÷ 2 = 185 932 + 1;
  • 185 932 ÷ 2 = 92 966 + 0;
  • 92 966 ÷ 2 = 46 483 + 0;
  • 46 483 ÷ 2 = 23 241 + 1;
  • 23 241 ÷ 2 = 11 620 + 1;
  • 11 620 ÷ 2 = 5 810 + 0;
  • 5 810 ÷ 2 = 2 905 + 0;
  • 2 905 ÷ 2 = 1 452 + 1;
  • 1 452 ÷ 2 = 726 + 0;
  • 726 ÷ 2 = 363 + 0;
  • 363 ÷ 2 = 181 + 1;
  • 181 ÷ 2 = 90 + 1;
  • 90 ÷ 2 = 45 + 0;
  • 45 ÷ 2 = 22 + 1;
  • 22 ÷ 2 = 11 + 0;
  • 11 ÷ 2 = 5 + 1;
  • 5 ÷ 2 = 2 + 1;
  • 2 ÷ 2 = 1 + 0;
  • 1 ÷ 2 = 0 + 1;

2. Construct the base 2 representation of the positive number:

Take all the remainders starting from the bottom of the list constructed above.

779 858 377 906(10) = 1011 0101 1001 0011 0010 1110 0111 1100 1011 0010(2)

3. Determine the signed binary number bit length:

  • The base 2 number's actual length, in bits: 40.

  • A signed binary's bit length must be equal to a power of 2, as of:
  • 21 = 2; 22 = 4; 23 = 8; 24 = 16; 25 = 32; 26 = 64; ...
  • The first bit (the leftmost) indicates the sign:
  • 0 = positive integer number, 1 = negative integer number

The least number that is:


1) a power of 2

2) and is larger than the actual length, 40,

3) so that the first bit (leftmost) could be zero
(we deal with a positive number at this moment)


=== is: 64.


4. Get the positive binary computer representation on 64 bits (8 Bytes):

If needed, add extra 0s in front (to the left) of the base 2 number, up to the required length, 64.


Decimal Number 779 858 377 906(10) converted to signed binary in two's complement representation:

779 858 377 906(10) = 0000 0000 0000 0000 0000 0000 1011 0101 1001 0011 0010 1110 0111 1100 1011 0010

Spaces were used to group digits: for binary, by 4, for decimal, by 3.


How to convert signed integers from decimal system to signed binary in two's complement representation

Follow the steps below to convert a signed base 10 integer number to signed binary in two's complement representation:

  • 1. If the number to be converted is negative, start with the positive version of the number.
  • 2. Divide repeatedly by 2 the positive representation of the integer number, keeping track of each remainder, until we get a quotient that is zero.
  • 3. Construct the base 2 representation of the positive number, by taking all the remainders starting from the bottom of the list constructed above. Thus, the last remainder of the divisions becomes the first symbol (the leftmost) of the base two number, while the first remainder becomes the last symbol (the rightmost).
  • 4. Binary numbers represented in computer language must have 4, 8, 16, 32, 64, ... bit length (a power of 2) - if needed, add extra bits on 0 in front (to the left) of the base 2 number above, up to the required length, so that the first bit (the leftmost) will be 0, correctly representing a positive number.
  • 5. To get the negative integer number representation in signed binary one's complement, replace all 0 bits with 1s and all 1 bits with 0s (reversing the digits).
  • 6. To get the negative integer number, in signed binary two's complement representation, add 1 to the number above.

Example: convert the negative number -60 from the decimal system (base ten) to signed binary in two's complement:

  • 1. Start with the positive version of the number: |-60| = 60
  • 2. Divide repeatedly 60 by 2, keeping track of each remainder:
    • division = quotient + remainder
    • 60 ÷ 2 = 30 + 0
    • 30 ÷ 2 = 15 + 0
    • 15 ÷ 2 = 7 + 1
    • 7 ÷ 2 = 3 + 1
    • 3 ÷ 2 = 1 + 1
    • 1 ÷ 2 = 0 + 1
  • 3. Construct the base 2 representation of the positive number, by taking all the remainders starting from the bottom of the list constructed above:
    60(10) = 11 1100(2)
  • 4. Bit length of base 2 representation number is 6, so the positive binary computer representation of a signed binary will take in this particular case 8 bits (the least power of 2 larger than 6) - add extra 0 digits in front of the base 2 number, up to the required length:
    60(10) = 0011 1100(2)
  • 5. To get the negative integer number representation in signed binary one's complement, replace all the 0 bits with 1s and all 1 bits with 0s (reversing the digits):
    !(0011 1100) = 1100 0011
  • 6. To get the negative integer number, signed binary in two's complement representation, add 1 to the number above:
    -60(10) = 1100 0011 + 1 = 1100 0100
  • Number -60(10), signed integer, converted from decimal system (base 10) to signed binary two's complement representation = 1100 0100