Convert -2 400 000 123 to a Signed Binary in Two's (2's) Complement Representation
How to convert decimal number -2 400 000 123(10) to a signed binary in two's (2's) complement representation
What are the steps to convert decimal number
-2 400 000 123 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:
|-2 400 000 123| = 2 400 000 123
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;
- 2 400 000 123 ÷ 2 = 1 200 000 061 + 1;
- 1 200 000 061 ÷ 2 = 600 000 030 + 1;
- 600 000 030 ÷ 2 = 300 000 015 + 0;
- 300 000 015 ÷ 2 = 150 000 007 + 1;
- 150 000 007 ÷ 2 = 75 000 003 + 1;
- 75 000 003 ÷ 2 = 37 500 001 + 1;
- 37 500 001 ÷ 2 = 18 750 000 + 1;
- 18 750 000 ÷ 2 = 9 375 000 + 0;
- 9 375 000 ÷ 2 = 4 687 500 + 0;
- 4 687 500 ÷ 2 = 2 343 750 + 0;
- 2 343 750 ÷ 2 = 1 171 875 + 0;
- 1 171 875 ÷ 2 = 585 937 + 1;
- 585 937 ÷ 2 = 292 968 + 1;
- 292 968 ÷ 2 = 146 484 + 0;
- 146 484 ÷ 2 = 73 242 + 0;
- 73 242 ÷ 2 = 36 621 + 0;
- 36 621 ÷ 2 = 18 310 + 1;
- 18 310 ÷ 2 = 9 155 + 0;
- 9 155 ÷ 2 = 4 577 + 1;
- 4 577 ÷ 2 = 2 288 + 1;
- 2 288 ÷ 2 = 1 144 + 0;
- 1 144 ÷ 2 = 572 + 0;
- 572 ÷ 2 = 286 + 0;
- 286 ÷ 2 = 143 + 0;
- 143 ÷ 2 = 71 + 1;
- 71 ÷ 2 = 35 + 1;
- 35 ÷ 2 = 17 + 1;
- 17 ÷ 2 = 8 + 1;
- 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.
2 400 000 123(10) = 1000 1111 0000 1101 0001 1000 0111 1011(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.
2 400 000 123(10) = 0000 0000 0000 0000 0000 0000 0000 0000 1000 1111 0000 1101 0001 1000 0111 1011
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 1111 0000 1101 0001 1000 0111 1011)
= 1111 1111 1111 1111 1111 1111 1111 1111 0111 0000 1111 0010 1110 0111 1000 0100
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 0000 1111 0010 1110 0111 1000 0100 (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):
-2 400 000 123 =
1111 1111 1111 1111 1111 1111 1111 1111 0111 0000 1111 0010 1110 0111 1000 0100 + 1
Decimal Number -2 400 000 123(10) converted to signed binary in two's complement representation:
-2 400 000 123(10) = 1111 1111 1111 1111 1111 1111 1111 1111 0111 0000 1111 0010 1110 0111 1000 0101
Spaces were used to group digits: for binary, by 4, for decimal, by 3.