What are the required steps to convert base 10 integer
number -378 223 090 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:
|-378 223 090| = 378 223 090
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;
- 378 223 090 ÷ 2 = 189 111 545 + 0;
- 189 111 545 ÷ 2 = 94 555 772 + 1;
- 94 555 772 ÷ 2 = 47 277 886 + 0;
- 47 277 886 ÷ 2 = 23 638 943 + 0;
- 23 638 943 ÷ 2 = 11 819 471 + 1;
- 11 819 471 ÷ 2 = 5 909 735 + 1;
- 5 909 735 ÷ 2 = 2 954 867 + 1;
- 2 954 867 ÷ 2 = 1 477 433 + 1;
- 1 477 433 ÷ 2 = 738 716 + 1;
- 738 716 ÷ 2 = 369 358 + 0;
- 369 358 ÷ 2 = 184 679 + 0;
- 184 679 ÷ 2 = 92 339 + 1;
- 92 339 ÷ 2 = 46 169 + 1;
- 46 169 ÷ 2 = 23 084 + 1;
- 23 084 ÷ 2 = 11 542 + 0;
- 11 542 ÷ 2 = 5 771 + 0;
- 5 771 ÷ 2 = 2 885 + 1;
- 2 885 ÷ 2 = 1 442 + 1;
- 1 442 ÷ 2 = 721 + 0;
- 721 ÷ 2 = 360 + 1;
- 360 ÷ 2 = 180 + 0;
- 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.
378 223 090(10) = 1 0110 1000 1011 0011 1001 1111 0010(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 29.
- 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, 29,
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:
378 223 090(10) = 0001 0110 1000 1011 0011 1001 1111 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...
-378 223 090(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-378 223 090(10) = 1001 0110 1000 1011 0011 1001 1111 0010
Spaces were used to group digits: for binary, by 4, for decimal, by 3.