Convert -379 904 685 to a Signed Binary in Two's (2's) Complement Representation
How to convert decimal number -379 904 685(10) to a signed binary in two's (2's) complement representation
What are the steps to convert decimal number
-379 904 685 to a signed binary in two's (2's) complement representation?
- 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:
|-379 904 685| = 379 904 685
2. 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;
- 379 904 685 ÷ 2 = 189 952 342 + 1;
- 189 952 342 ÷ 2 = 94 976 171 + 0;
- 94 976 171 ÷ 2 = 47 488 085 + 1;
- 47 488 085 ÷ 2 = 23 744 042 + 1;
- 23 744 042 ÷ 2 = 11 872 021 + 0;
- 11 872 021 ÷ 2 = 5 936 010 + 1;
- 5 936 010 ÷ 2 = 2 968 005 + 0;
- 2 968 005 ÷ 2 = 1 484 002 + 1;
- 1 484 002 ÷ 2 = 742 001 + 0;
- 742 001 ÷ 2 = 371 000 + 1;
- 371 000 ÷ 2 = 185 500 + 0;
- 185 500 ÷ 2 = 92 750 + 0;
- 92 750 ÷ 2 = 46 375 + 0;
- 46 375 ÷ 2 = 23 187 + 1;
- 23 187 ÷ 2 = 11 593 + 1;
- 11 593 ÷ 2 = 5 796 + 1;
- 5 796 ÷ 2 = 2 898 + 0;
- 2 898 ÷ 2 = 1 449 + 0;
- 1 449 ÷ 2 = 724 + 1;
- 724 ÷ 2 = 362 + 0;
- 362 ÷ 2 = 181 + 0;
- 181 ÷ 2 = 90 + 1;
- 90 ÷ 2 = 45 + 0;
- 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.
379 904 685(10) = 1 0110 1010 0100 1110 0010 1010 1101(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 29.
- 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, 29,
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.
379 904 685(10) = 0001 0110 1010 0100 1110 0010 1010 1101
6. Get the negative integer number representation. Part 1:
- To write the negative integer number on 32 bits (4 Bytes), as a signed binary in one's complement representation, replace all the bits on 0 with 1s and all the bits set on 1 with 0s.
Reverse the digits, flip the digits:
Replace the bits set on 0 with 1s and the bits set on 1 with 0s.
!(0001 0110 1010 0100 1110 0010 1010 1101)
= 1110 1001 0101 1011 0001 1101 0101 0010
7. Get the negative integer number representation. Part 2:
- To write the negative integer number on 32 bits (4 Bytes), as a signed binary in two's complement representation, add 1 to the number calculated above 1110 1001 0101 1011 0001 1101 0101 0010 (to the signed binary in one's complement representation).
Binary addition carries on a value of 2:
- 0 + 0 = 0
- 0 + 1 = 1
- 1 + 1 = 10
- 1 + 10 = 11
- 1 + 11 = 100
Add 1 to the number calculated above
(to the signed binary number in one's complement representation):
-379 904 685 =
1110 1001 0101 1011 0001 1101 0101 0010 + 1
Decimal Number -379 904 685(10) converted to signed binary in two's complement representation:
-379 904 685(10) = 1110 1001 0101 1011 0001 1101 0101 0011
Spaces were used to group digits: for binary, by 4, for decimal, by 3.