What are the required steps to convert base 10 integer
number -395 142 888 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:
|-395 142 888| = 395 142 888
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;
- 395 142 888 ÷ 2 = 197 571 444 + 0;
- 197 571 444 ÷ 2 = 98 785 722 + 0;
- 98 785 722 ÷ 2 = 49 392 861 + 0;
- 49 392 861 ÷ 2 = 24 696 430 + 1;
- 24 696 430 ÷ 2 = 12 348 215 + 0;
- 12 348 215 ÷ 2 = 6 174 107 + 1;
- 6 174 107 ÷ 2 = 3 087 053 + 1;
- 3 087 053 ÷ 2 = 1 543 526 + 1;
- 1 543 526 ÷ 2 = 771 763 + 0;
- 771 763 ÷ 2 = 385 881 + 1;
- 385 881 ÷ 2 = 192 940 + 1;
- 192 940 ÷ 2 = 96 470 + 0;
- 96 470 ÷ 2 = 48 235 + 0;
- 48 235 ÷ 2 = 24 117 + 1;
- 24 117 ÷ 2 = 12 058 + 1;
- 12 058 ÷ 2 = 6 029 + 0;
- 6 029 ÷ 2 = 3 014 + 1;
- 3 014 ÷ 2 = 1 507 + 0;
- 1 507 ÷ 2 = 753 + 1;
- 753 ÷ 2 = 376 + 1;
- 376 ÷ 2 = 188 + 0;
- 188 ÷ 2 = 94 + 0;
- 94 ÷ 2 = 47 + 0;
- 47 ÷ 2 = 23 + 1;
- 23 ÷ 2 = 11 + 1;
- 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.
395 142 888(10) = 1 0111 1000 1101 0110 0110 1110 1000(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 29.
- 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, 29,
3) so that the first bit (leftmost) could be zero
(we deal with a positive number at this moment)
=== is: 32.
5. Get the positive binary computer representation on 32 bits (4 Bytes):
If needed, add extra 0s in front (to the left) of the base 2 number, up to the required length, 32:
395 142 888(10) = 0001 0111 1000 1101 0110 0110 1110 1000
6. Get the negative integer number representation:
To get the negative integer number representation on 32 bits (4 Bytes),
... change the first bit (the leftmost), from 0 to 1...
-395 142 888(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-395 142 888(10) = 1001 0111 1000 1101 0110 0110 1110 1000
Spaces were used to group digits: for binary, by 4, for decimal, by 3.