What are the required steps to convert base 10 integer
number -289 229 853 136 545 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:
|-289 229 853 136 545| = 289 229 853 136 545
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;
- 289 229 853 136 545 ÷ 2 = 144 614 926 568 272 + 1;
- 144 614 926 568 272 ÷ 2 = 72 307 463 284 136 + 0;
- 72 307 463 284 136 ÷ 2 = 36 153 731 642 068 + 0;
- 36 153 731 642 068 ÷ 2 = 18 076 865 821 034 + 0;
- 18 076 865 821 034 ÷ 2 = 9 038 432 910 517 + 0;
- 9 038 432 910 517 ÷ 2 = 4 519 216 455 258 + 1;
- 4 519 216 455 258 ÷ 2 = 2 259 608 227 629 + 0;
- 2 259 608 227 629 ÷ 2 = 1 129 804 113 814 + 1;
- 1 129 804 113 814 ÷ 2 = 564 902 056 907 + 0;
- 564 902 056 907 ÷ 2 = 282 451 028 453 + 1;
- 282 451 028 453 ÷ 2 = 141 225 514 226 + 1;
- 141 225 514 226 ÷ 2 = 70 612 757 113 + 0;
- 70 612 757 113 ÷ 2 = 35 306 378 556 + 1;
- 35 306 378 556 ÷ 2 = 17 653 189 278 + 0;
- 17 653 189 278 ÷ 2 = 8 826 594 639 + 0;
- 8 826 594 639 ÷ 2 = 4 413 297 319 + 1;
- 4 413 297 319 ÷ 2 = 2 206 648 659 + 1;
- 2 206 648 659 ÷ 2 = 1 103 324 329 + 1;
- 1 103 324 329 ÷ 2 = 551 662 164 + 1;
- 551 662 164 ÷ 2 = 275 831 082 + 0;
- 275 831 082 ÷ 2 = 137 915 541 + 0;
- 137 915 541 ÷ 2 = 68 957 770 + 1;
- 68 957 770 ÷ 2 = 34 478 885 + 0;
- 34 478 885 ÷ 2 = 17 239 442 + 1;
- 17 239 442 ÷ 2 = 8 619 721 + 0;
- 8 619 721 ÷ 2 = 4 309 860 + 1;
- 4 309 860 ÷ 2 = 2 154 930 + 0;
- 2 154 930 ÷ 2 = 1 077 465 + 0;
- 1 077 465 ÷ 2 = 538 732 + 1;
- 538 732 ÷ 2 = 269 366 + 0;
- 269 366 ÷ 2 = 134 683 + 0;
- 134 683 ÷ 2 = 67 341 + 1;
- 67 341 ÷ 2 = 33 670 + 1;
- 33 670 ÷ 2 = 16 835 + 0;
- 16 835 ÷ 2 = 8 417 + 1;
- 8 417 ÷ 2 = 4 208 + 1;
- 4 208 ÷ 2 = 2 104 + 0;
- 2 104 ÷ 2 = 1 052 + 0;
- 1 052 ÷ 2 = 526 + 0;
- 526 ÷ 2 = 263 + 0;
- 263 ÷ 2 = 131 + 1;
- 131 ÷ 2 = 65 + 1;
- 65 ÷ 2 = 32 + 1;
- 32 ÷ 2 = 16 + 0;
- 16 ÷ 2 = 8 + 0;
- 8 ÷ 2 = 4 + 0;
- 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.
289 229 853 136 545(10) = 1 0000 0111 0000 1101 1001 0010 1010 0111 1001 0110 1010 0001(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 49.
- 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, 49,
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:
289 229 853 136 545(10) = 0000 0000 0000 0001 0000 0111 0000 1101 1001 0010 1010 0111 1001 0110 1010 0001
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...
-289 229 853 136 545(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-289 229 853 136 545(10) = 1000 0000 0000 0001 0000 0111 0000 1101 1001 0010 1010 0111 1001 0110 1010 0001
Spaces were used to group digits: for binary, by 4, for decimal, by 3.