What are the required steps to convert base 10 integer
number -73 505 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:
|-73 505| = 73 505
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;
- 73 505 ÷ 2 = 36 752 + 1;
- 36 752 ÷ 2 = 18 376 + 0;
- 18 376 ÷ 2 = 9 188 + 0;
- 9 188 ÷ 2 = 4 594 + 0;
- 4 594 ÷ 2 = 2 297 + 0;
- 2 297 ÷ 2 = 1 148 + 1;
- 1 148 ÷ 2 = 574 + 0;
- 574 ÷ 2 = 287 + 0;
- 287 ÷ 2 = 143 + 1;
- 143 ÷ 2 = 71 + 1;
- 71 ÷ 2 = 35 + 1;
- 35 ÷ 2 = 17 + 1;
- 17 ÷ 2 = 8 + 1;
- 8 ÷ 2 = 4 + 0;
- 4 ÷ 2 = 2 + 0;
- 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.
73 505(10) = 1 0001 1111 0010 0001(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 17.
- 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, 17,
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:
73 505(10) = 0000 0000 0000 0001 0001 1111 0010 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...
-73 505(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-73 505(10) = 1000 0000 0000 0001 0001 1111 0010 0001
Spaces were used to group digits: for binary, by 4, for decimal, by 3.