What are the required steps to convert base 10 integer
number -1 988 795 266 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:
|-1 988 795 266| = 1 988 795 266
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;
- 1 988 795 266 ÷ 2 = 994 397 633 + 0;
- 994 397 633 ÷ 2 = 497 198 816 + 1;
- 497 198 816 ÷ 2 = 248 599 408 + 0;
- 248 599 408 ÷ 2 = 124 299 704 + 0;
- 124 299 704 ÷ 2 = 62 149 852 + 0;
- 62 149 852 ÷ 2 = 31 074 926 + 0;
- 31 074 926 ÷ 2 = 15 537 463 + 0;
- 15 537 463 ÷ 2 = 7 768 731 + 1;
- 7 768 731 ÷ 2 = 3 884 365 + 1;
- 3 884 365 ÷ 2 = 1 942 182 + 1;
- 1 942 182 ÷ 2 = 971 091 + 0;
- 971 091 ÷ 2 = 485 545 + 1;
- 485 545 ÷ 2 = 242 772 + 1;
- 242 772 ÷ 2 = 121 386 + 0;
- 121 386 ÷ 2 = 60 693 + 0;
- 60 693 ÷ 2 = 30 346 + 1;
- 30 346 ÷ 2 = 15 173 + 0;
- 15 173 ÷ 2 = 7 586 + 1;
- 7 586 ÷ 2 = 3 793 + 0;
- 3 793 ÷ 2 = 1 896 + 1;
- 1 896 ÷ 2 = 948 + 0;
- 948 ÷ 2 = 474 + 0;
- 474 ÷ 2 = 237 + 0;
- 237 ÷ 2 = 118 + 1;
- 118 ÷ 2 = 59 + 0;
- 59 ÷ 2 = 29 + 1;
- 29 ÷ 2 = 14 + 1;
- 14 ÷ 2 = 7 + 0;
- 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.
1 988 795 266(10) = 111 0110 1000 1010 1001 1011 1000 0010(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:
1 988 795 266(10) = 0111 0110 1000 1010 1001 1011 1000 0010
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...
-1 988 795 266(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-1 988 795 266(10) = 1111 0110 1000 1010 1001 1011 1000 0010
Spaces were used to group digits: for binary, by 4, for decimal, by 3.