Convert -10 000 000 242 to a Signed Binary in Two's (2's) Complement Representation
How to convert decimal number -10 000 000 242(10) to a signed binary in two's (2's) complement representation
What are the steps to convert decimal number
-10 000 000 242 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:
|-10 000 000 242| = 10 000 000 242
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;
- 10 000 000 242 ÷ 2 = 5 000 000 121 + 0;
- 5 000 000 121 ÷ 2 = 2 500 000 060 + 1;
- 2 500 000 060 ÷ 2 = 1 250 000 030 + 0;
- 1 250 000 030 ÷ 2 = 625 000 015 + 0;
- 625 000 015 ÷ 2 = 312 500 007 + 1;
- 312 500 007 ÷ 2 = 156 250 003 + 1;
- 156 250 003 ÷ 2 = 78 125 001 + 1;
- 78 125 001 ÷ 2 = 39 062 500 + 1;
- 39 062 500 ÷ 2 = 19 531 250 + 0;
- 19 531 250 ÷ 2 = 9 765 625 + 0;
- 9 765 625 ÷ 2 = 4 882 812 + 1;
- 4 882 812 ÷ 2 = 2 441 406 + 0;
- 2 441 406 ÷ 2 = 1 220 703 + 0;
- 1 220 703 ÷ 2 = 610 351 + 1;
- 610 351 ÷ 2 = 305 175 + 1;
- 305 175 ÷ 2 = 152 587 + 1;
- 152 587 ÷ 2 = 76 293 + 1;
- 76 293 ÷ 2 = 38 146 + 1;
- 38 146 ÷ 2 = 19 073 + 0;
- 19 073 ÷ 2 = 9 536 + 1;
- 9 536 ÷ 2 = 4 768 + 0;
- 4 768 ÷ 2 = 2 384 + 0;
- 2 384 ÷ 2 = 1 192 + 0;
- 1 192 ÷ 2 = 596 + 0;
- 596 ÷ 2 = 298 + 0;
- 298 ÷ 2 = 149 + 0;
- 149 ÷ 2 = 74 + 1;
- 74 ÷ 2 = 37 + 0;
- 37 ÷ 2 = 18 + 1;
- 18 ÷ 2 = 9 + 0;
- 9 ÷ 2 = 4 + 1;
- 4 ÷ 2 = 2 + 0;
- 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.
10 000 000 242(10) = 10 0101 0100 0000 1011 1110 0100 1111 0010(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 34.
- 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, 34,
3) so that the first bit (leftmost) could be zero
(we deal with a positive number at this moment)
=== is: 64.
5. Get the positive binary computer representation on 64 bits (8 Bytes):
If needed, add extra 0s in front (to the left) of the base 2 number, up to the required length, 64.
10 000 000 242(10) = 0000 0000 0000 0000 0000 0000 0000 0010 0101 0100 0000 1011 1110 0100 1111 0010
6. Get the negative integer number representation. Part 1:
- To write the negative integer number on 64 bits (8 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.
!(0000 0000 0000 0000 0000 0000 0000 0010 0101 0100 0000 1011 1110 0100 1111 0010)
= 1111 1111 1111 1111 1111 1111 1111 1101 1010 1011 1111 0100 0001 1011 0000 1101
7. Get the negative integer number representation. Part 2:
- To write the negative integer number on 64 bits (8 Bytes), as a signed binary in two's complement representation, add 1 to the number calculated above 1111 1111 1111 1111 1111 1111 1111 1101 1010 1011 1111 0100 0001 1011 0000 1101 (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):
-10 000 000 242 =
1111 1111 1111 1111 1111 1111 1111 1101 1010 1011 1111 0100 0001 1011 0000 1101 + 1
Decimal Number -10 000 000 242(10) converted to signed binary in two's complement representation:
-10 000 000 242(10) = 1111 1111 1111 1111 1111 1111 1111 1101 1010 1011 1111 0100 0001 1011 0000 1110
Spaces were used to group digits: for binary, by 4, for decimal, by 3.