Convert 4 000 000 000 000 000 805 to a Signed Binary (Base 2)

How to convert 4 000 000 000 000 000 805(10), a signed base 10 integer number? How to write it as a signed binary code in base 2

What are the required steps to convert base 10 integer
number 4 000 000 000 000 000 805 to signed binary code (in base 2)?

  • 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.

Stop when you get a quotient that is equal to zero.


  • division = quotient + remainder;
  • 4 000 000 000 000 000 805 ÷ 2 = 2 000 000 000 000 000 402 + 1;
  • 2 000 000 000 000 000 402 ÷ 2 = 1 000 000 000 000 000 201 + 0;
  • 1 000 000 000 000 000 201 ÷ 2 = 500 000 000 000 000 100 + 1;
  • 500 000 000 000 000 100 ÷ 2 = 250 000 000 000 000 050 + 0;
  • 250 000 000 000 000 050 ÷ 2 = 125 000 000 000 000 025 + 0;
  • 125 000 000 000 000 025 ÷ 2 = 62 500 000 000 000 012 + 1;
  • 62 500 000 000 000 012 ÷ 2 = 31 250 000 000 000 006 + 0;
  • 31 250 000 000 000 006 ÷ 2 = 15 625 000 000 000 003 + 0;
  • 15 625 000 000 000 003 ÷ 2 = 7 812 500 000 000 001 + 1;
  • 7 812 500 000 000 001 ÷ 2 = 3 906 250 000 000 000 + 1;
  • 3 906 250 000 000 000 ÷ 2 = 1 953 125 000 000 000 + 0;
  • 1 953 125 000 000 000 ÷ 2 = 976 562 500 000 000 + 0;
  • 976 562 500 000 000 ÷ 2 = 488 281 250 000 000 + 0;
  • 488 281 250 000 000 ÷ 2 = 244 140 625 000 000 + 0;
  • 244 140 625 000 000 ÷ 2 = 122 070 312 500 000 + 0;
  • 122 070 312 500 000 ÷ 2 = 61 035 156 250 000 + 0;
  • 61 035 156 250 000 ÷ 2 = 30 517 578 125 000 + 0;
  • 30 517 578 125 000 ÷ 2 = 15 258 789 062 500 + 0;
  • 15 258 789 062 500 ÷ 2 = 7 629 394 531 250 + 0;
  • 7 629 394 531 250 ÷ 2 = 3 814 697 265 625 + 0;
  • 3 814 697 265 625 ÷ 2 = 1 907 348 632 812 + 1;
  • 1 907 348 632 812 ÷ 2 = 953 674 316 406 + 0;
  • 953 674 316 406 ÷ 2 = 476 837 158 203 + 0;
  • 476 837 158 203 ÷ 2 = 238 418 579 101 + 1;
  • 238 418 579 101 ÷ 2 = 119 209 289 550 + 1;
  • 119 209 289 550 ÷ 2 = 59 604 644 775 + 0;
  • 59 604 644 775 ÷ 2 = 29 802 322 387 + 1;
  • 29 802 322 387 ÷ 2 = 14 901 161 193 + 1;
  • 14 901 161 193 ÷ 2 = 7 450 580 596 + 1;
  • 7 450 580 596 ÷ 2 = 3 725 290 298 + 0;
  • 3 725 290 298 ÷ 2 = 1 862 645 149 + 0;
  • 1 862 645 149 ÷ 2 = 931 322 574 + 1;
  • 931 322 574 ÷ 2 = 465 661 287 + 0;
  • 465 661 287 ÷ 2 = 232 830 643 + 1;
  • 232 830 643 ÷ 2 = 116 415 321 + 1;
  • 116 415 321 ÷ 2 = 58 207 660 + 1;
  • 58 207 660 ÷ 2 = 29 103 830 + 0;
  • 29 103 830 ÷ 2 = 14 551 915 + 0;
  • 14 551 915 ÷ 2 = 7 275 957 + 1;
  • 7 275 957 ÷ 2 = 3 637 978 + 1;
  • 3 637 978 ÷ 2 = 1 818 989 + 0;
  • 1 818 989 ÷ 2 = 909 494 + 1;
  • 909 494 ÷ 2 = 454 747 + 0;
  • 454 747 ÷ 2 = 227 373 + 1;
  • 227 373 ÷ 2 = 113 686 + 1;
  • 113 686 ÷ 2 = 56 843 + 0;
  • 56 843 ÷ 2 = 28 421 + 1;
  • 28 421 ÷ 2 = 14 210 + 1;
  • 14 210 ÷ 2 = 7 105 + 0;
  • 7 105 ÷ 2 = 3 552 + 1;
  • 3 552 ÷ 2 = 1 776 + 0;
  • 1 776 ÷ 2 = 888 + 0;
  • 888 ÷ 2 = 444 + 0;
  • 444 ÷ 2 = 222 + 0;
  • 222 ÷ 2 = 111 + 0;
  • 111 ÷ 2 = 55 + 1;
  • 55 ÷ 2 = 27 + 1;
  • 27 ÷ 2 = 13 + 1;
  • 13 ÷ 2 = 6 + 1;
  • 6 ÷ 2 = 3 + 0;
  • 3 ÷ 2 = 1 + 1;
  • 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.

4 000 000 000 000 000 805(10) = 11 0111 1000 0010 1101 1010 1100 1110 1001 1101 1001 0000 0000 0011 0010 0101(2)


3. Determine the signed binary number bit length:

  • The base 2 number's actual length, in bits: 62.

  • 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) is reserved for 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, 62,

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:


4 000 000 000 000 000 805(10) Base 10 integer number converted and written as a signed binary code (in base 2):

4 000 000 000 000 000 805(10) = 0011 0111 1000 0010 1101 1010 1100 1110 1001 1101 1001 0000 0000 0011 0010 0101

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

How to convert signed base 10 integers in decimal to binary code system

Follow the steps below to convert a signed base ten integer number to signed binary:

  • 1. In a signed binary, first bit (the leftmost) is reserved for sign: 0 = positive integer number, 1 = positive integer number. If the number to be converted is negative, start with its positive version.
  • 2. Divide repeatedly by 2 the positive integer number keeping track of each remainder. STOP when 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 have a length of 4, 8, 16, 32, 64, ... bits (power of 2) - if needed, fill in extra '0' bits in front of the base 2 number (to the left), up to the right length; this way the first bit (the leftmost one) is always '0', as for a positive representation.
  • 5. To get the negative reprezentation of the number, simply switch the first bit (the leftmost one), from '0' to '1'.

Example: convert the negative number -63 from decimal system (base ten) to signed binary code system:

  • 1. Start with the positive version of the number: |-63| = 63;
  • 2. Divide repeatedly 63 by 2, keeping track of each remainder, until we get a quotient that is equal to zero:
    • division = quotient + remainder
    • 63 ÷ 2 = 31 + 1
    • 31 ÷ 2 = 15 + 1
    • 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:
    63(10) = 11 1111(2)
  • 4. The actual length of base 2 representation number is 6, so the positive binary computer representation length of the signed binary will take in this case 8 bits (the least power of 2 higher than 6) - add extra '0's in front (to the left), up to the required length; this way the first bit (the leftmost one) is to be '0', as for a positive number:
    63(10) = 0011 1111(2)
  • 5. To get the negative integer number representation simply change the first bit (the leftmost), from '0' to '1':
    -63(10) = 1011 1111
  • Number -63(10), signed integer, converted from decimal system (base 10) to signed binary = 1011 1111