What are the required steps to convert base 10 integer
number -127 703 336 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:
|-127 703 336| = 127 703 336
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;
- 127 703 336 ÷ 2 = 63 851 668 + 0;
- 63 851 668 ÷ 2 = 31 925 834 + 0;
- 31 925 834 ÷ 2 = 15 962 917 + 0;
- 15 962 917 ÷ 2 = 7 981 458 + 1;
- 7 981 458 ÷ 2 = 3 990 729 + 0;
- 3 990 729 ÷ 2 = 1 995 364 + 1;
- 1 995 364 ÷ 2 = 997 682 + 0;
- 997 682 ÷ 2 = 498 841 + 0;
- 498 841 ÷ 2 = 249 420 + 1;
- 249 420 ÷ 2 = 124 710 + 0;
- 124 710 ÷ 2 = 62 355 + 0;
- 62 355 ÷ 2 = 31 177 + 1;
- 31 177 ÷ 2 = 15 588 + 1;
- 15 588 ÷ 2 = 7 794 + 0;
- 7 794 ÷ 2 = 3 897 + 0;
- 3 897 ÷ 2 = 1 948 + 1;
- 1 948 ÷ 2 = 974 + 0;
- 974 ÷ 2 = 487 + 0;
- 487 ÷ 2 = 243 + 1;
- 243 ÷ 2 = 121 + 1;
- 121 ÷ 2 = 60 + 1;
- 60 ÷ 2 = 30 + 0;
- 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.
127 703 336(10) = 111 1001 1100 1001 1001 0010 1000(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 27.
- 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, 27,
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:
127 703 336(10) = 0000 0111 1001 1100 1001 1001 0010 1000
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...
-127 703 336(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-127 703 336(10) = 1000 0111 1001 1100 1001 1001 0010 1000
Spaces were used to group digits: for binary, by 4, for decimal, by 3.