What are the required steps to convert base 10 integer
number -945 113 651 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:
|-945 113 651| = 945 113 651
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;
- 945 113 651 ÷ 2 = 472 556 825 + 1;
- 472 556 825 ÷ 2 = 236 278 412 + 1;
- 236 278 412 ÷ 2 = 118 139 206 + 0;
- 118 139 206 ÷ 2 = 59 069 603 + 0;
- 59 069 603 ÷ 2 = 29 534 801 + 1;
- 29 534 801 ÷ 2 = 14 767 400 + 1;
- 14 767 400 ÷ 2 = 7 383 700 + 0;
- 7 383 700 ÷ 2 = 3 691 850 + 0;
- 3 691 850 ÷ 2 = 1 845 925 + 0;
- 1 845 925 ÷ 2 = 922 962 + 1;
- 922 962 ÷ 2 = 461 481 + 0;
- 461 481 ÷ 2 = 230 740 + 1;
- 230 740 ÷ 2 = 115 370 + 0;
- 115 370 ÷ 2 = 57 685 + 0;
- 57 685 ÷ 2 = 28 842 + 1;
- 28 842 ÷ 2 = 14 421 + 0;
- 14 421 ÷ 2 = 7 210 + 1;
- 7 210 ÷ 2 = 3 605 + 0;
- 3 605 ÷ 2 = 1 802 + 1;
- 1 802 ÷ 2 = 901 + 0;
- 901 ÷ 2 = 450 + 1;
- 450 ÷ 2 = 225 + 0;
- 225 ÷ 2 = 112 + 1;
- 112 ÷ 2 = 56 + 0;
- 56 ÷ 2 = 28 + 0;
- 28 ÷ 2 = 14 + 0;
- 14 ÷ 2 = 7 + 0;
- 7 ÷ 2 = 3 + 1;
- 3 ÷ 2 = 1 + 1;
- 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.
945 113 651(10) = 11 1000 0101 0101 0100 1010 0011 0011(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 30.
- 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, 30,
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:
945 113 651(10) = 0011 1000 0101 0101 0100 1010 0011 0011
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...
-945 113 651(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-945 113 651(10) = 1011 1000 0101 0101 0100 1010 0011 0011
Spaces were used to group digits: for binary, by 4, for decimal, by 3.