What are the required steps to convert base 10 integer
number 21 389 183 800 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;
- 21 389 183 800 ÷ 2 = 10 694 591 900 + 0;
- 10 694 591 900 ÷ 2 = 5 347 295 950 + 0;
- 5 347 295 950 ÷ 2 = 2 673 647 975 + 0;
- 2 673 647 975 ÷ 2 = 1 336 823 987 + 1;
- 1 336 823 987 ÷ 2 = 668 411 993 + 1;
- 668 411 993 ÷ 2 = 334 205 996 + 1;
- 334 205 996 ÷ 2 = 167 102 998 + 0;
- 167 102 998 ÷ 2 = 83 551 499 + 0;
- 83 551 499 ÷ 2 = 41 775 749 + 1;
- 41 775 749 ÷ 2 = 20 887 874 + 1;
- 20 887 874 ÷ 2 = 10 443 937 + 0;
- 10 443 937 ÷ 2 = 5 221 968 + 1;
- 5 221 968 ÷ 2 = 2 610 984 + 0;
- 2 610 984 ÷ 2 = 1 305 492 + 0;
- 1 305 492 ÷ 2 = 652 746 + 0;
- 652 746 ÷ 2 = 326 373 + 0;
- 326 373 ÷ 2 = 163 186 + 1;
- 163 186 ÷ 2 = 81 593 + 0;
- 81 593 ÷ 2 = 40 796 + 1;
- 40 796 ÷ 2 = 20 398 + 0;
- 20 398 ÷ 2 = 10 199 + 0;
- 10 199 ÷ 2 = 5 099 + 1;
- 5 099 ÷ 2 = 2 549 + 1;
- 2 549 ÷ 2 = 1 274 + 1;
- 1 274 ÷ 2 = 637 + 0;
- 637 ÷ 2 = 318 + 1;
- 318 ÷ 2 = 159 + 0;
- 159 ÷ 2 = 79 + 1;
- 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;
2. Construct the base 2 representation of the positive number:
Take all the remainders starting from the bottom of the list constructed above.
21 389 183 800(10) = 100 1111 1010 1110 0101 0000 1011 0011 1000(2)
3. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 35.
- 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, 35,
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:
21 389 183 800(10) Base 10 integer number converted and written as a signed binary code (in base 2):
21 389 183 800(10) = 0000 0000 0000 0000 0000 0000 0000 0100 1111 1010 1110 0101 0000 1011 0011 1000
Spaces were used to group digits: for binary, by 4, for decimal, by 3.