What are the required steps to convert base 10 integer
number -2 147 428 012 to signed binary code (in base 2)?
- 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:
|-2 147 428 012| = 2 147 428 012
2. Divide the number repeatedly by 2:
Keep track of each remainder.
Stop when you get a quotient that is equal to zero.
- division = quotient + remainder;
- 2 147 428 012 ÷ 2 = 1 073 714 006 + 0;
- 1 073 714 006 ÷ 2 = 536 857 003 + 0;
- 536 857 003 ÷ 2 = 268 428 501 + 1;
- 268 428 501 ÷ 2 = 134 214 250 + 1;
- 134 214 250 ÷ 2 = 67 107 125 + 0;
- 67 107 125 ÷ 2 = 33 553 562 + 1;
- 33 553 562 ÷ 2 = 16 776 781 + 0;
- 16 776 781 ÷ 2 = 8 388 390 + 1;
- 8 388 390 ÷ 2 = 4 194 195 + 0;
- 4 194 195 ÷ 2 = 2 097 097 + 1;
- 2 097 097 ÷ 2 = 1 048 548 + 1;
- 1 048 548 ÷ 2 = 524 274 + 0;
- 524 274 ÷ 2 = 262 137 + 0;
- 262 137 ÷ 2 = 131 068 + 1;
- 131 068 ÷ 2 = 65 534 + 0;
- 65 534 ÷ 2 = 32 767 + 0;
- 32 767 ÷ 2 = 16 383 + 1;
- 16 383 ÷ 2 = 8 191 + 1;
- 8 191 ÷ 2 = 4 095 + 1;
- 4 095 ÷ 2 = 2 047 + 1;
- 2 047 ÷ 2 = 1 023 + 1;
- 1 023 ÷ 2 = 511 + 1;
- 511 ÷ 2 = 255 + 1;
- 255 ÷ 2 = 127 + 1;
- 127 ÷ 2 = 63 + 1;
- 63 ÷ 2 = 31 + 1;
- 31 ÷ 2 = 15 + 1;
- 15 ÷ 2 = 7 + 1;
- 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.
2 147 428 012(10) = 111 1111 1111 1111 0010 0110 1010 1100(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 31.
- 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) is reserved for 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, 31,
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:
2 147 428 012(10) = 0111 1111 1111 1111 0010 0110 1010 1100
6. Get the negative integer number representation:
To get the negative integer number representation on 32 bits (4 Bytes),
... change the first bit (the leftmost), from 0 to 1...
-2 147 428 012(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-2 147 428 012(10) = 1111 1111 1111 1111 0010 0110 1010 1100
Spaces were used to group digits: for binary, by 4, for decimal, by 3.