1. Divide the number repeatedly by 2:
Keep track of each remainder.
We stop when we get a quotient that is equal to zero.
- division = quotient + remainder;
- 641 974 ÷ 2 = 320 987 + 0;
- 320 987 ÷ 2 = 160 493 + 1;
- 160 493 ÷ 2 = 80 246 + 1;
- 80 246 ÷ 2 = 40 123 + 0;
- 40 123 ÷ 2 = 20 061 + 1;
- 20 061 ÷ 2 = 10 030 + 1;
- 10 030 ÷ 2 = 5 015 + 0;
- 5 015 ÷ 2 = 2 507 + 1;
- 2 507 ÷ 2 = 1 253 + 1;
- 1 253 ÷ 2 = 626 + 1;
- 626 ÷ 2 = 313 + 0;
- 313 ÷ 2 = 156 + 1;
- 156 ÷ 2 = 78 + 0;
- 78 ÷ 2 = 39 + 0;
- 39 ÷ 2 = 19 + 1;
- 19 ÷ 2 = 9 + 1;
- 9 ÷ 2 = 4 + 1;
- 4 ÷ 2 = 2 + 0;
- 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.
641 974(10) = 1001 1100 1011 1011 0110(2)
3. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 20.
- 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) indicates 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, 20,
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.
Decimal Number 641 974(10) converted to signed binary in two's complement representation:
Spaces were used to group digits: for binary, by 4, for decimal, by 3.