What are the required steps to convert base 10 integer
number -47 787 913 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:
|-47 787 913| = 47 787 913
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;
- 47 787 913 ÷ 2 = 23 893 956 + 1;
- 23 893 956 ÷ 2 = 11 946 978 + 0;
- 11 946 978 ÷ 2 = 5 973 489 + 0;
- 5 973 489 ÷ 2 = 2 986 744 + 1;
- 2 986 744 ÷ 2 = 1 493 372 + 0;
- 1 493 372 ÷ 2 = 746 686 + 0;
- 746 686 ÷ 2 = 373 343 + 0;
- 373 343 ÷ 2 = 186 671 + 1;
- 186 671 ÷ 2 = 93 335 + 1;
- 93 335 ÷ 2 = 46 667 + 1;
- 46 667 ÷ 2 = 23 333 + 1;
- 23 333 ÷ 2 = 11 666 + 1;
- 11 666 ÷ 2 = 5 833 + 0;
- 5 833 ÷ 2 = 2 916 + 1;
- 2 916 ÷ 2 = 1 458 + 0;
- 1 458 ÷ 2 = 729 + 0;
- 729 ÷ 2 = 364 + 1;
- 364 ÷ 2 = 182 + 0;
- 182 ÷ 2 = 91 + 0;
- 91 ÷ 2 = 45 + 1;
- 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.
47 787 913(10) = 10 1101 1001 0010 1111 1000 1001(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 26.
- 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, 26,
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:
47 787 913(10) = 0000 0010 1101 1001 0010 1111 1000 1001
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...
-47 787 913(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-47 787 913(10) = 1000 0010 1101 1001 0010 1111 1000 1001
Spaces were used to group digits: for binary, by 4, for decimal, by 3.