What are the required steps to convert base 10 integer
number -1 148 598 270 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:
|-1 148 598 270| = 1 148 598 270
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;
- 1 148 598 270 ÷ 2 = 574 299 135 + 0;
- 574 299 135 ÷ 2 = 287 149 567 + 1;
- 287 149 567 ÷ 2 = 143 574 783 + 1;
- 143 574 783 ÷ 2 = 71 787 391 + 1;
- 71 787 391 ÷ 2 = 35 893 695 + 1;
- 35 893 695 ÷ 2 = 17 946 847 + 1;
- 17 946 847 ÷ 2 = 8 973 423 + 1;
- 8 973 423 ÷ 2 = 4 486 711 + 1;
- 4 486 711 ÷ 2 = 2 243 355 + 1;
- 2 243 355 ÷ 2 = 1 121 677 + 1;
- 1 121 677 ÷ 2 = 560 838 + 1;
- 560 838 ÷ 2 = 280 419 + 0;
- 280 419 ÷ 2 = 140 209 + 1;
- 140 209 ÷ 2 = 70 104 + 1;
- 70 104 ÷ 2 = 35 052 + 0;
- 35 052 ÷ 2 = 17 526 + 0;
- 17 526 ÷ 2 = 8 763 + 0;
- 8 763 ÷ 2 = 4 381 + 1;
- 4 381 ÷ 2 = 2 190 + 1;
- 2 190 ÷ 2 = 1 095 + 0;
- 1 095 ÷ 2 = 547 + 1;
- 547 ÷ 2 = 273 + 1;
- 273 ÷ 2 = 136 + 1;
- 136 ÷ 2 = 68 + 0;
- 68 ÷ 2 = 34 + 0;
- 34 ÷ 2 = 17 + 0;
- 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.
1 148 598 270(10) = 100 0100 0111 0110 0011 0111 1111 1110(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:
1 148 598 270(10) = 0100 0100 0111 0110 0011 0111 1111 1110
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...
-1 148 598 270(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-1 148 598 270(10) = 1100 0100 0111 0110 0011 0111 1111 1110
Spaces were used to group digits: for binary, by 4, for decimal, by 3.