What are the required steps to convert base 10 integer
number -1 515 870 492 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:
|-1 515 870 492| = 1 515 870 492
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;
- 1 515 870 492 ÷ 2 = 757 935 246 + 0;
- 757 935 246 ÷ 2 = 378 967 623 + 0;
- 378 967 623 ÷ 2 = 189 483 811 + 1;
- 189 483 811 ÷ 2 = 94 741 905 + 1;
- 94 741 905 ÷ 2 = 47 370 952 + 1;
- 47 370 952 ÷ 2 = 23 685 476 + 0;
- 23 685 476 ÷ 2 = 11 842 738 + 0;
- 11 842 738 ÷ 2 = 5 921 369 + 0;
- 5 921 369 ÷ 2 = 2 960 684 + 1;
- 2 960 684 ÷ 2 = 1 480 342 + 0;
- 1 480 342 ÷ 2 = 740 171 + 0;
- 740 171 ÷ 2 = 370 085 + 1;
- 370 085 ÷ 2 = 185 042 + 1;
- 185 042 ÷ 2 = 92 521 + 0;
- 92 521 ÷ 2 = 46 260 + 1;
- 46 260 ÷ 2 = 23 130 + 0;
- 23 130 ÷ 2 = 11 565 + 0;
- 11 565 ÷ 2 = 5 782 + 1;
- 5 782 ÷ 2 = 2 891 + 0;
- 2 891 ÷ 2 = 1 445 + 1;
- 1 445 ÷ 2 = 722 + 1;
- 722 ÷ 2 = 361 + 0;
- 361 ÷ 2 = 180 + 1;
- 180 ÷ 2 = 90 + 0;
- 90 ÷ 2 = 45 + 0;
- 45 ÷ 2 = 22 + 1;
- 22 ÷ 2 = 11 + 0;
- 11 ÷ 2 = 5 + 1;
- 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.
1 515 870 492(10) = 101 1010 0101 1010 0101 1001 0001 1100(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 31.
- 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, 31,
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:
1 515 870 492(10) = 0101 1010 0101 1010 0101 1001 0001 1100
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...
-1 515 870 492(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-1 515 870 492(10) = 1101 1010 0101 1010 0101 1001 0001 1100
Spaces were used to group digits: for binary, by 4, for decimal, by 3.