Convert -2 147 483 689 to a Signed Binary in Two's (2's) Complement Representation
How to convert decimal number -2 147 483 689(10) to a signed binary in two's (2's) complement representation
What are the steps to convert decimal number
-2 147 483 689 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:
|-2 147 483 689| = 2 147 483 689
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;
- 2 147 483 689 ÷ 2 = 1 073 741 844 + 1;
- 1 073 741 844 ÷ 2 = 536 870 922 + 0;
- 536 870 922 ÷ 2 = 268 435 461 + 0;
- 268 435 461 ÷ 2 = 134 217 730 + 1;
- 134 217 730 ÷ 2 = 67 108 865 + 0;
- 67 108 865 ÷ 2 = 33 554 432 + 1;
- 33 554 432 ÷ 2 = 16 777 216 + 0;
- 16 777 216 ÷ 2 = 8 388 608 + 0;
- 8 388 608 ÷ 2 = 4 194 304 + 0;
- 4 194 304 ÷ 2 = 2 097 152 + 0;
- 2 097 152 ÷ 2 = 1 048 576 + 0;
- 1 048 576 ÷ 2 = 524 288 + 0;
- 524 288 ÷ 2 = 262 144 + 0;
- 262 144 ÷ 2 = 131 072 + 0;
- 131 072 ÷ 2 = 65 536 + 0;
- 65 536 ÷ 2 = 32 768 + 0;
- 32 768 ÷ 2 = 16 384 + 0;
- 16 384 ÷ 2 = 8 192 + 0;
- 8 192 ÷ 2 = 4 096 + 0;
- 4 096 ÷ 2 = 2 048 + 0;
- 2 048 ÷ 2 = 1 024 + 0;
- 1 024 ÷ 2 = 512 + 0;
- 512 ÷ 2 = 256 + 0;
- 256 ÷ 2 = 128 + 0;
- 128 ÷ 2 = 64 + 0;
- 64 ÷ 2 = 32 + 0;
- 32 ÷ 2 = 16 + 0;
- 16 ÷ 2 = 8 + 0;
- 8 ÷ 2 = 4 + 0;
- 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.
2 147 483 689(10) = 1000 0000 0000 0000 0000 0000 0010 1001(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 32.
- 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, 32,
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.
2 147 483 689(10) = 0000 0000 0000 0000 0000 0000 0000 0000 1000 0000 0000 0000 0000 0000 0010 1001
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 0000 1000 0000 0000 0000 0000 0000 0010 1001)
= 1111 1111 1111 1111 1111 1111 1111 1111 0111 1111 1111 1111 1111 1111 1101 0110
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 1111 0111 1111 1111 1111 1111 1111 1101 0110 (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):
-2 147 483 689 =
1111 1111 1111 1111 1111 1111 1111 1111 0111 1111 1111 1111 1111 1111 1101 0110 + 1
Decimal Number -2 147 483 689(10) converted to signed binary in two's complement representation:
-2 147 483 689(10) = 1111 1111 1111 1111 1111 1111 1111 1111 0111 1111 1111 1111 1111 1111 1101 0111
Spaces were used to group digits: for binary, by 4, for decimal, by 3.