What are the required steps to convert base 10 integer
number -675 628 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:
|-675 628| = 675 628
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;
- 675 628 ÷ 2 = 337 814 + 0;
- 337 814 ÷ 2 = 168 907 + 0;
- 168 907 ÷ 2 = 84 453 + 1;
- 84 453 ÷ 2 = 42 226 + 1;
- 42 226 ÷ 2 = 21 113 + 0;
- 21 113 ÷ 2 = 10 556 + 1;
- 10 556 ÷ 2 = 5 278 + 0;
- 5 278 ÷ 2 = 2 639 + 0;
- 2 639 ÷ 2 = 1 319 + 1;
- 1 319 ÷ 2 = 659 + 1;
- 659 ÷ 2 = 329 + 1;
- 329 ÷ 2 = 164 + 1;
- 164 ÷ 2 = 82 + 0;
- 82 ÷ 2 = 41 + 0;
- 41 ÷ 2 = 20 + 1;
- 20 ÷ 2 = 10 + 0;
- 10 ÷ 2 = 5 + 0;
- 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.
675 628(10) = 1010 0100 1111 0010 1100(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 20.
- 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, 20,
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:
675 628(10) = 0000 0000 0000 1010 0100 1111 0010 1100
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...
-675 628(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-675 628(10) = 1000 0000 0000 1010 0100 1111 0010 1100
Spaces were used to group digits: for binary, by 4, for decimal, by 3.