What are the required steps to convert base 10 integer
number -188 370 875 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:
|-188 370 875| = 188 370 875
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;
- 188 370 875 ÷ 2 = 94 185 437 + 1;
- 94 185 437 ÷ 2 = 47 092 718 + 1;
- 47 092 718 ÷ 2 = 23 546 359 + 0;
- 23 546 359 ÷ 2 = 11 773 179 + 1;
- 11 773 179 ÷ 2 = 5 886 589 + 1;
- 5 886 589 ÷ 2 = 2 943 294 + 1;
- 2 943 294 ÷ 2 = 1 471 647 + 0;
- 1 471 647 ÷ 2 = 735 823 + 1;
- 735 823 ÷ 2 = 367 911 + 1;
- 367 911 ÷ 2 = 183 955 + 1;
- 183 955 ÷ 2 = 91 977 + 1;
- 91 977 ÷ 2 = 45 988 + 1;
- 45 988 ÷ 2 = 22 994 + 0;
- 22 994 ÷ 2 = 11 497 + 0;
- 11 497 ÷ 2 = 5 748 + 1;
- 5 748 ÷ 2 = 2 874 + 0;
- 2 874 ÷ 2 = 1 437 + 0;
- 1 437 ÷ 2 = 718 + 1;
- 718 ÷ 2 = 359 + 0;
- 359 ÷ 2 = 179 + 1;
- 179 ÷ 2 = 89 + 1;
- 89 ÷ 2 = 44 + 1;
- 44 ÷ 2 = 22 + 0;
- 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.
188 370 875(10) = 1011 0011 1010 0100 1111 1011 1011(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 28.
- 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, 28,
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:
188 370 875(10) = 0000 1011 0011 1010 0100 1111 1011 1011
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...
-188 370 875(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-188 370 875(10) = 1000 1011 0011 1010 0100 1111 1011 1011
Spaces were used to group digits: for binary, by 4, for decimal, by 3.