Convert -99 999 999 415 to a Signed Binary in Two's (2's) Complement Representation
How to convert decimal number -99 999 999 415(10) to a signed binary in two's (2's) complement representation
What are the steps to convert decimal number
-99 999 999 415 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:
|-99 999 999 415| = 99 999 999 415
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;
- 99 999 999 415 ÷ 2 = 49 999 999 707 + 1;
- 49 999 999 707 ÷ 2 = 24 999 999 853 + 1;
- 24 999 999 853 ÷ 2 = 12 499 999 926 + 1;
- 12 499 999 926 ÷ 2 = 6 249 999 963 + 0;
- 6 249 999 963 ÷ 2 = 3 124 999 981 + 1;
- 3 124 999 981 ÷ 2 = 1 562 499 990 + 1;
- 1 562 499 990 ÷ 2 = 781 249 995 + 0;
- 781 249 995 ÷ 2 = 390 624 997 + 1;
- 390 624 997 ÷ 2 = 195 312 498 + 1;
- 195 312 498 ÷ 2 = 97 656 249 + 0;
- 97 656 249 ÷ 2 = 48 828 124 + 1;
- 48 828 124 ÷ 2 = 24 414 062 + 0;
- 24 414 062 ÷ 2 = 12 207 031 + 0;
- 12 207 031 ÷ 2 = 6 103 515 + 1;
- 6 103 515 ÷ 2 = 3 051 757 + 1;
- 3 051 757 ÷ 2 = 1 525 878 + 1;
- 1 525 878 ÷ 2 = 762 939 + 0;
- 762 939 ÷ 2 = 381 469 + 1;
- 381 469 ÷ 2 = 190 734 + 1;
- 190 734 ÷ 2 = 95 367 + 0;
- 95 367 ÷ 2 = 47 683 + 1;
- 47 683 ÷ 2 = 23 841 + 1;
- 23 841 ÷ 2 = 11 920 + 1;
- 11 920 ÷ 2 = 5 960 + 0;
- 5 960 ÷ 2 = 2 980 + 0;
- 2 980 ÷ 2 = 1 490 + 0;
- 1 490 ÷ 2 = 745 + 0;
- 745 ÷ 2 = 372 + 1;
- 372 ÷ 2 = 186 + 0;
- 186 ÷ 2 = 93 + 0;
- 93 ÷ 2 = 46 + 1;
- 46 ÷ 2 = 23 + 0;
- 23 ÷ 2 = 11 + 1;
- 11 ÷ 2 = 5 + 1;
- 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.
99 999 999 415(10) = 1 0111 0100 1000 0111 0110 1110 0101 1011 0111(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 37.
- 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, 37,
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.
99 999 999 415(10) = 0000 0000 0000 0000 0000 0000 0001 0111 0100 1000 0111 0110 1110 0101 1011 0111
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 0001 0111 0100 1000 0111 0110 1110 0101 1011 0111)
= 1111 1111 1111 1111 1111 1111 1110 1000 1011 0111 1000 1001 0001 1010 0100 1000
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 1110 1000 1011 0111 1000 1001 0001 1010 0100 1000 (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):
-99 999 999 415 =
1111 1111 1111 1111 1111 1111 1110 1000 1011 0111 1000 1001 0001 1010 0100 1000 + 1
Decimal Number -99 999 999 415(10) converted to signed binary in two's complement representation:
-99 999 999 415(10) = 1111 1111 1111 1111 1111 1111 1110 1000 1011 0111 1000 1001 0001 1010 0100 1001
Spaces were used to group digits: for binary, by 4, for decimal, by 3.