Convert -167 772 421 to a Signed Binary in Two's (2's) Complement Representation
How to convert decimal number -167 772 421(10) to a signed binary in two's (2's) complement representation
What are the steps to convert decimal number
-167 772 421 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:
|-167 772 421| = 167 772 421
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;
- 167 772 421 ÷ 2 = 83 886 210 + 1;
- 83 886 210 ÷ 2 = 41 943 105 + 0;
- 41 943 105 ÷ 2 = 20 971 552 + 1;
- 20 971 552 ÷ 2 = 10 485 776 + 0;
- 10 485 776 ÷ 2 = 5 242 888 + 0;
- 5 242 888 ÷ 2 = 2 621 444 + 0;
- 2 621 444 ÷ 2 = 1 310 722 + 0;
- 1 310 722 ÷ 2 = 655 361 + 0;
- 655 361 ÷ 2 = 327 680 + 1;
- 327 680 ÷ 2 = 163 840 + 0;
- 163 840 ÷ 2 = 81 920 + 0;
- 81 920 ÷ 2 = 40 960 + 0;
- 40 960 ÷ 2 = 20 480 + 0;
- 20 480 ÷ 2 = 10 240 + 0;
- 10 240 ÷ 2 = 5 120 + 0;
- 5 120 ÷ 2 = 2 560 + 0;
- 2 560 ÷ 2 = 1 280 + 0;
- 1 280 ÷ 2 = 640 + 0;
- 640 ÷ 2 = 320 + 0;
- 320 ÷ 2 = 160 + 0;
- 160 ÷ 2 = 80 + 0;
- 80 ÷ 2 = 40 + 0;
- 40 ÷ 2 = 20 + 0;
- 20 ÷ 2 = 10 + 0;
- 10 ÷ 2 = 5 + 0;
- 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.
167 772 421(10) = 1010 0000 0000 0000 0001 0000 0101(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 28.
- 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, 28,
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.
167 772 421(10) = 0000 1010 0000 0000 0000 0001 0000 0101
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.
!(0000 1010 0000 0000 0000 0001 0000 0101)
= 1111 0101 1111 1111 1111 1110 1111 1010
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 1111 0101 1111 1111 1111 1110 1111 1010 (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):
-167 772 421 =
1111 0101 1111 1111 1111 1110 1111 1010 + 1
Decimal Number -167 772 421(10) converted to signed binary in two's complement representation:
-167 772 421(10) = 1111 0101 1111 1111 1111 1110 1111 1011
Spaces were used to group digits: for binary, by 4, for decimal, by 3.