What are the required steps to convert base 10 integer
number -397 801 709 542 425 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:
|-397 801 709 542 425| = 397 801 709 542 425
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;
- 397 801 709 542 425 ÷ 2 = 198 900 854 771 212 + 1;
- 198 900 854 771 212 ÷ 2 = 99 450 427 385 606 + 0;
- 99 450 427 385 606 ÷ 2 = 49 725 213 692 803 + 0;
- 49 725 213 692 803 ÷ 2 = 24 862 606 846 401 + 1;
- 24 862 606 846 401 ÷ 2 = 12 431 303 423 200 + 1;
- 12 431 303 423 200 ÷ 2 = 6 215 651 711 600 + 0;
- 6 215 651 711 600 ÷ 2 = 3 107 825 855 800 + 0;
- 3 107 825 855 800 ÷ 2 = 1 553 912 927 900 + 0;
- 1 553 912 927 900 ÷ 2 = 776 956 463 950 + 0;
- 776 956 463 950 ÷ 2 = 388 478 231 975 + 0;
- 388 478 231 975 ÷ 2 = 194 239 115 987 + 1;
- 194 239 115 987 ÷ 2 = 97 119 557 993 + 1;
- 97 119 557 993 ÷ 2 = 48 559 778 996 + 1;
- 48 559 778 996 ÷ 2 = 24 279 889 498 + 0;
- 24 279 889 498 ÷ 2 = 12 139 944 749 + 0;
- 12 139 944 749 ÷ 2 = 6 069 972 374 + 1;
- 6 069 972 374 ÷ 2 = 3 034 986 187 + 0;
- 3 034 986 187 ÷ 2 = 1 517 493 093 + 1;
- 1 517 493 093 ÷ 2 = 758 746 546 + 1;
- 758 746 546 ÷ 2 = 379 373 273 + 0;
- 379 373 273 ÷ 2 = 189 686 636 + 1;
- 189 686 636 ÷ 2 = 94 843 318 + 0;
- 94 843 318 ÷ 2 = 47 421 659 + 0;
- 47 421 659 ÷ 2 = 23 710 829 + 1;
- 23 710 829 ÷ 2 = 11 855 414 + 1;
- 11 855 414 ÷ 2 = 5 927 707 + 0;
- 5 927 707 ÷ 2 = 2 963 853 + 1;
- 2 963 853 ÷ 2 = 1 481 926 + 1;
- 1 481 926 ÷ 2 = 740 963 + 0;
- 740 963 ÷ 2 = 370 481 + 1;
- 370 481 ÷ 2 = 185 240 + 1;
- 185 240 ÷ 2 = 92 620 + 0;
- 92 620 ÷ 2 = 46 310 + 0;
- 46 310 ÷ 2 = 23 155 + 0;
- 23 155 ÷ 2 = 11 577 + 1;
- 11 577 ÷ 2 = 5 788 + 1;
- 5 788 ÷ 2 = 2 894 + 0;
- 2 894 ÷ 2 = 1 447 + 0;
- 1 447 ÷ 2 = 723 + 1;
- 723 ÷ 2 = 361 + 1;
- 361 ÷ 2 = 180 + 1;
- 180 ÷ 2 = 90 + 0;
- 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;
3. Construct the base 2 representation of the positive number:
Take all the remainders starting from the bottom of the list constructed above.
397 801 709 542 425(10) = 1 0110 1001 1100 1100 0110 1101 1001 0110 1001 1100 0001 1001(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:
397 801 709 542 425(10) = 0000 0000 0000 0001 0110 1001 1100 1100 0110 1101 1001 0110 1001 1100 0001 1001
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...
-397 801 709 542 425(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-397 801 709 542 425(10) = 1000 0000 0000 0001 0110 1001 1100 1100 0110 1101 1001 0110 1001 1100 0001 1001
Spaces were used to group digits: for binary, by 4, for decimal, by 3.