What are the required steps to convert base 10 integer
number -22 590 289 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:
|-22 590 289| = 22 590 289
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;
- 22 590 289 ÷ 2 = 11 295 144 + 1;
- 11 295 144 ÷ 2 = 5 647 572 + 0;
- 5 647 572 ÷ 2 = 2 823 786 + 0;
- 2 823 786 ÷ 2 = 1 411 893 + 0;
- 1 411 893 ÷ 2 = 705 946 + 1;
- 705 946 ÷ 2 = 352 973 + 0;
- 352 973 ÷ 2 = 176 486 + 1;
- 176 486 ÷ 2 = 88 243 + 0;
- 88 243 ÷ 2 = 44 121 + 1;
- 44 121 ÷ 2 = 22 060 + 1;
- 22 060 ÷ 2 = 11 030 + 0;
- 11 030 ÷ 2 = 5 515 + 0;
- 5 515 ÷ 2 = 2 757 + 1;
- 2 757 ÷ 2 = 1 378 + 1;
- 1 378 ÷ 2 = 689 + 0;
- 689 ÷ 2 = 344 + 1;
- 344 ÷ 2 = 172 + 0;
- 172 ÷ 2 = 86 + 0;
- 86 ÷ 2 = 43 + 0;
- 43 ÷ 2 = 21 + 1;
- 21 ÷ 2 = 10 + 1;
- 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.
22 590 289(10) = 1 0101 1000 1011 0011 0101 0001(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 25.
- 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, 25,
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:
22 590 289(10) = 0000 0001 0101 1000 1011 0011 0101 0001
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...
-22 590 289(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-22 590 289(10) = 1000 0001 0101 1000 1011 0011 0101 0001
Spaces were used to group digits: for binary, by 4, for decimal, by 3.