Convert -61 642 208 to a Signed Binary in Two's (2's) Complement Representation
How to convert decimal number -61 642 208(10) to a signed binary in two's (2's) complement representation
What are the steps to convert decimal number
-61 642 208 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:
|-61 642 208| = 61 642 208
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;
- 61 642 208 ÷ 2 = 30 821 104 + 0;
- 30 821 104 ÷ 2 = 15 410 552 + 0;
- 15 410 552 ÷ 2 = 7 705 276 + 0;
- 7 705 276 ÷ 2 = 3 852 638 + 0;
- 3 852 638 ÷ 2 = 1 926 319 + 0;
- 1 926 319 ÷ 2 = 963 159 + 1;
- 963 159 ÷ 2 = 481 579 + 1;
- 481 579 ÷ 2 = 240 789 + 1;
- 240 789 ÷ 2 = 120 394 + 1;
- 120 394 ÷ 2 = 60 197 + 0;
- 60 197 ÷ 2 = 30 098 + 1;
- 30 098 ÷ 2 = 15 049 + 0;
- 15 049 ÷ 2 = 7 524 + 1;
- 7 524 ÷ 2 = 3 762 + 0;
- 3 762 ÷ 2 = 1 881 + 0;
- 1 881 ÷ 2 = 940 + 1;
- 940 ÷ 2 = 470 + 0;
- 470 ÷ 2 = 235 + 0;
- 235 ÷ 2 = 117 + 1;
- 117 ÷ 2 = 58 + 1;
- 58 ÷ 2 = 29 + 0;
- 29 ÷ 2 = 14 + 1;
- 14 ÷ 2 = 7 + 0;
- 7 ÷ 2 = 3 + 1;
- 3 ÷ 2 = 1 + 1;
- 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.
61 642 208(10) = 11 1010 1100 1001 0101 1110 0000(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 26.
- 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, 26,
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.
61 642 208(10) = 0000 0011 1010 1100 1001 0101 1110 0000
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 0011 1010 1100 1001 0101 1110 0000)
= 1111 1100 0101 0011 0110 1010 0001 1111
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 1100 0101 0011 0110 1010 0001 1111 (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):
-61 642 208 =
1111 1100 0101 0011 0110 1010 0001 1111 + 1
Decimal Number -61 642 208(10) converted to signed binary in two's complement representation:
-61 642 208(10) = 1111 1100 0101 0011 0110 1010 0010 0000
Spaces were used to group digits: for binary, by 4, for decimal, by 3.