What are the required steps to convert base 10 integer
number -6 291 425 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:
|-6 291 425| = 6 291 425
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;
- 6 291 425 ÷ 2 = 3 145 712 + 1;
- 3 145 712 ÷ 2 = 1 572 856 + 0;
- 1 572 856 ÷ 2 = 786 428 + 0;
- 786 428 ÷ 2 = 393 214 + 0;
- 393 214 ÷ 2 = 196 607 + 0;
- 196 607 ÷ 2 = 98 303 + 1;
- 98 303 ÷ 2 = 49 151 + 1;
- 49 151 ÷ 2 = 24 575 + 1;
- 24 575 ÷ 2 = 12 287 + 1;
- 12 287 ÷ 2 = 6 143 + 1;
- 6 143 ÷ 2 = 3 071 + 1;
- 3 071 ÷ 2 = 1 535 + 1;
- 1 535 ÷ 2 = 767 + 1;
- 767 ÷ 2 = 383 + 1;
- 383 ÷ 2 = 191 + 1;
- 191 ÷ 2 = 95 + 1;
- 95 ÷ 2 = 47 + 1;
- 47 ÷ 2 = 23 + 1;
- 23 ÷ 2 = 11 + 1;
- 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.
6 291 425(10) = 101 1111 1111 1111 1110 0001(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 23.
- 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, 23,
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:
6 291 425(10) = 0000 0000 0101 1111 1111 1111 1110 0001
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...
-6 291 425(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-6 291 425(10) = 1000 0000 0101 1111 1111 1111 1110 0001
Spaces were used to group digits: for binary, by 4, for decimal, by 3.