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;
- 100 000 000 000 000 125 ÷ 2 = 50 000 000 000 000 062 + 1;
- 50 000 000 000 000 062 ÷ 2 = 25 000 000 000 000 031 + 0;
- 25 000 000 000 000 031 ÷ 2 = 12 500 000 000 000 015 + 1;
- 12 500 000 000 000 015 ÷ 2 = 6 250 000 000 000 007 + 1;
- 6 250 000 000 000 007 ÷ 2 = 3 125 000 000 000 003 + 1;
- 3 125 000 000 000 003 ÷ 2 = 1 562 500 000 000 001 + 1;
- 1 562 500 000 000 001 ÷ 2 = 781 250 000 000 000 + 1;
- 781 250 000 000 000 ÷ 2 = 390 625 000 000 000 + 0;
- 390 625 000 000 000 ÷ 2 = 195 312 500 000 000 + 0;
- 195 312 500 000 000 ÷ 2 = 97 656 250 000 000 + 0;
- 97 656 250 000 000 ÷ 2 = 48 828 125 000 000 + 0;
- 48 828 125 000 000 ÷ 2 = 24 414 062 500 000 + 0;
- 24 414 062 500 000 ÷ 2 = 12 207 031 250 000 + 0;
- 12 207 031 250 000 ÷ 2 = 6 103 515 625 000 + 0;
- 6 103 515 625 000 ÷ 2 = 3 051 757 812 500 + 0;
- 3 051 757 812 500 ÷ 2 = 1 525 878 906 250 + 0;
- 1 525 878 906 250 ÷ 2 = 762 939 453 125 + 0;
- 762 939 453 125 ÷ 2 = 381 469 726 562 + 1;
- 381 469 726 562 ÷ 2 = 190 734 863 281 + 0;
- 190 734 863 281 ÷ 2 = 95 367 431 640 + 1;
- 95 367 431 640 ÷ 2 = 47 683 715 820 + 0;
- 47 683 715 820 ÷ 2 = 23 841 857 910 + 0;
- 23 841 857 910 ÷ 2 = 11 920 928 955 + 0;
- 11 920 928 955 ÷ 2 = 5 960 464 477 + 1;
- 5 960 464 477 ÷ 2 = 2 980 232 238 + 1;
- 2 980 232 238 ÷ 2 = 1 490 116 119 + 0;
- 1 490 116 119 ÷ 2 = 745 058 059 + 1;
- 745 058 059 ÷ 2 = 372 529 029 + 1;
- 372 529 029 ÷ 2 = 186 264 514 + 1;
- 186 264 514 ÷ 2 = 93 132 257 + 0;
- 93 132 257 ÷ 2 = 46 566 128 + 1;
- 46 566 128 ÷ 2 = 23 283 064 + 0;
- 23 283 064 ÷ 2 = 11 641 532 + 0;
- 11 641 532 ÷ 2 = 5 820 766 + 0;
- 5 820 766 ÷ 2 = 2 910 383 + 0;
- 2 910 383 ÷ 2 = 1 455 191 + 1;
- 1 455 191 ÷ 2 = 727 595 + 1;
- 727 595 ÷ 2 = 363 797 + 1;
- 363 797 ÷ 2 = 181 898 + 1;
- 181 898 ÷ 2 = 90 949 + 0;
- 90 949 ÷ 2 = 45 474 + 1;
- 45 474 ÷ 2 = 22 737 + 0;
- 22 737 ÷ 2 = 11 368 + 1;
- 11 368 ÷ 2 = 5 684 + 0;
- 5 684 ÷ 2 = 2 842 + 0;
- 2 842 ÷ 2 = 1 421 + 0;
- 1 421 ÷ 2 = 710 + 1;
- 710 ÷ 2 = 355 + 0;
- 355 ÷ 2 = 177 + 1;
- 177 ÷ 2 = 88 + 1;
- 88 ÷ 2 = 44 + 0;
- 44 ÷ 2 = 22 + 0;
- 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.
100 000 000 000 000 125(10) = 1 0110 0011 0100 0101 0111 1000 0101 1101 1000 1010 0000 0000 0111 1101(2)
3. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 57.
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, 57,
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.
Number 100 000 000 000 000 125(10), a signed integer number (with sign), converted from decimal system (from base 10) and written as a signed binary in two's complement representation:
100 000 000 000 000 125(10) = 0000 0001 0110 0011 0100 0101 0111 1000 0101 1101 1000 1010 0000 0000 0111 1101
Spaces were used to group digits: for binary, by 4, for decimal, by 3.