What are the required steps to convert base 10 integer
number -2 657 174 563 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. Start with the positive version of the number:
|-2 657 174 563| = 2 657 174 563
2. 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;
- 2 657 174 563 ÷ 2 = 1 328 587 281 + 1;
- 1 328 587 281 ÷ 2 = 664 293 640 + 1;
- 664 293 640 ÷ 2 = 332 146 820 + 0;
- 332 146 820 ÷ 2 = 166 073 410 + 0;
- 166 073 410 ÷ 2 = 83 036 705 + 0;
- 83 036 705 ÷ 2 = 41 518 352 + 1;
- 41 518 352 ÷ 2 = 20 759 176 + 0;
- 20 759 176 ÷ 2 = 10 379 588 + 0;
- 10 379 588 ÷ 2 = 5 189 794 + 0;
- 5 189 794 ÷ 2 = 2 594 897 + 0;
- 2 594 897 ÷ 2 = 1 297 448 + 1;
- 1 297 448 ÷ 2 = 648 724 + 0;
- 648 724 ÷ 2 = 324 362 + 0;
- 324 362 ÷ 2 = 162 181 + 0;
- 162 181 ÷ 2 = 81 090 + 1;
- 81 090 ÷ 2 = 40 545 + 0;
- 40 545 ÷ 2 = 20 272 + 1;
- 20 272 ÷ 2 = 10 136 + 0;
- 10 136 ÷ 2 = 5 068 + 0;
- 5 068 ÷ 2 = 2 534 + 0;
- 2 534 ÷ 2 = 1 267 + 0;
- 1 267 ÷ 2 = 633 + 1;
- 633 ÷ 2 = 316 + 1;
- 316 ÷ 2 = 158 + 0;
- 158 ÷ 2 = 79 + 0;
- 79 ÷ 2 = 39 + 1;
- 39 ÷ 2 = 19 + 1;
- 19 ÷ 2 = 9 + 1;
- 9 ÷ 2 = 4 + 1;
- 4 ÷ 2 = 2 + 0;
- 2 ÷ 2 = 1 + 0;
- 1 ÷ 2 = 0 + 1;
3. Construct the base 2 representation of the positive number:
Take all the remainders starting from the bottom of the list constructed above.
2 657 174 563(10) = 1001 1110 0110 0001 0100 0100 0010 0011(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 32.
- 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, 32,
3) so that the first bit (leftmost) could be zero
(we deal with a positive number at this moment)
=== is: 64.
5. 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:
2 657 174 563(10) = 0000 0000 0000 0000 0000 0000 0000 0000 1001 1110 0110 0001 0100 0100 0010 0011
6. Get the negative integer number representation:
To get the negative integer number representation on 64 bits (8 Bytes),
... change the first bit (the leftmost), from 0 to 1...
-2 657 174 563(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-2 657 174 563(10) = 1000 0000 0000 0000 0000 0000 0000 0000 1001 1110 0110 0001 0100 0100 0010 0011
Spaces were used to group digits: for binary, by 4, for decimal, by 3.