What are the required steps to convert base 10 integer
number -31 416 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:
|-31 416| = 31 416
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;
- 31 416 ÷ 2 = 15 708 + 0;
- 15 708 ÷ 2 = 7 854 + 0;
- 7 854 ÷ 2 = 3 927 + 0;
- 3 927 ÷ 2 = 1 963 + 1;
- 1 963 ÷ 2 = 981 + 1;
- 981 ÷ 2 = 490 + 1;
- 490 ÷ 2 = 245 + 0;
- 245 ÷ 2 = 122 + 1;
- 122 ÷ 2 = 61 + 0;
- 61 ÷ 2 = 30 + 1;
- 30 ÷ 2 = 15 + 0;
- 15 ÷ 2 = 7 + 1;
- 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.
31 416(10) = 111 1010 1011 1000(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 15.
- 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, 15,
3) so that the first bit (leftmost) could be zero
(we deal with a positive number at this moment)
=== is: 16.
5. Get the positive binary computer representation on 16 bits (2 Bytes):
If needed, add extra 0s in front (to the left) of the base 2 number, up to the required length, 16:
31 416(10) = 0111 1010 1011 1000
6. Get the negative integer number representation:
To get the negative integer number representation on 16 bits (2 Bytes),
... change the first bit (the leftmost), from 0 to 1...
-31 416(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-31 416(10) = 1111 1010 1011 1000
Spaces were used to group digits: for binary, by 4, for decimal, by 3.