What are the required steps to convert base 10 integer
number 15 643 131 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. 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;
- 15 643 131 ÷ 2 = 7 821 565 + 1;
- 7 821 565 ÷ 2 = 3 910 782 + 1;
- 3 910 782 ÷ 2 = 1 955 391 + 0;
- 1 955 391 ÷ 2 = 977 695 + 1;
- 977 695 ÷ 2 = 488 847 + 1;
- 488 847 ÷ 2 = 244 423 + 1;
- 244 423 ÷ 2 = 122 211 + 1;
- 122 211 ÷ 2 = 61 105 + 1;
- 61 105 ÷ 2 = 30 552 + 1;
- 30 552 ÷ 2 = 15 276 + 0;
- 15 276 ÷ 2 = 7 638 + 0;
- 7 638 ÷ 2 = 3 819 + 0;
- 3 819 ÷ 2 = 1 909 + 1;
- 1 909 ÷ 2 = 954 + 1;
- 954 ÷ 2 = 477 + 0;
- 477 ÷ 2 = 238 + 1;
- 238 ÷ 2 = 119 + 0;
- 119 ÷ 2 = 59 + 1;
- 59 ÷ 2 = 29 + 1;
- 29 ÷ 2 = 14 + 1;
- 14 ÷ 2 = 7 + 0;
- 7 ÷ 2 = 3 + 1;
- 3 ÷ 2 = 1 + 1;
- 1 ÷ 2 = 0 + 1;
2. Construct the base 2 representation of the positive number:
Take all the remainders starting from the bottom of the list constructed above.
15 643 131(10) = 1110 1110 1011 0001 1111 1011(2)
3. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 24.
- 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, 24,
3) so that the first bit (leftmost) could be zero
(we deal with a positive number at this moment)
=== is: 32.
4. 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:
15 643 131(10) Base 10 integer number converted and written as a signed binary code (in base 2):
15 643 131(10) = 0000 0000 1110 1110 1011 0001 1111 1011
Spaces were used to group digits: for binary, by 4, for decimal, by 3.