What are the required steps to convert base 10 integer
number 21 051 978 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;
- 21 051 978 ÷ 2 = 10 525 989 + 0;
- 10 525 989 ÷ 2 = 5 262 994 + 1;
- 5 262 994 ÷ 2 = 2 631 497 + 0;
- 2 631 497 ÷ 2 = 1 315 748 + 1;
- 1 315 748 ÷ 2 = 657 874 + 0;
- 657 874 ÷ 2 = 328 937 + 0;
- 328 937 ÷ 2 = 164 468 + 1;
- 164 468 ÷ 2 = 82 234 + 0;
- 82 234 ÷ 2 = 41 117 + 0;
- 41 117 ÷ 2 = 20 558 + 1;
- 20 558 ÷ 2 = 10 279 + 0;
- 10 279 ÷ 2 = 5 139 + 1;
- 5 139 ÷ 2 = 2 569 + 1;
- 2 569 ÷ 2 = 1 284 + 1;
- 1 284 ÷ 2 = 642 + 0;
- 642 ÷ 2 = 321 + 0;
- 321 ÷ 2 = 160 + 1;
- 160 ÷ 2 = 80 + 0;
- 80 ÷ 2 = 40 + 0;
- 40 ÷ 2 = 20 + 0;
- 20 ÷ 2 = 10 + 0;
- 10 ÷ 2 = 5 + 0;
- 5 ÷ 2 = 2 + 1;
- 2 ÷ 2 = 1 + 0;
- 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.
21 051 978(10) = 1 0100 0001 0011 1010 0100 1010(2)
3. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 25.
- 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, 25,
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:
21 051 978(10) Base 10 integer number converted and written as a signed binary code (in base 2):
21 051 978(10) = 0000 0001 0100 0001 0011 1010 0100 1010
Spaces were used to group digits: for binary, by 4, for decimal, by 3.