What are the required steps to convert base 10 integer
number -80 978 463 292 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:
|-80 978 463 292| = 80 978 463 292
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;
- 80 978 463 292 ÷ 2 = 40 489 231 646 + 0;
- 40 489 231 646 ÷ 2 = 20 244 615 823 + 0;
- 20 244 615 823 ÷ 2 = 10 122 307 911 + 1;
- 10 122 307 911 ÷ 2 = 5 061 153 955 + 1;
- 5 061 153 955 ÷ 2 = 2 530 576 977 + 1;
- 2 530 576 977 ÷ 2 = 1 265 288 488 + 1;
- 1 265 288 488 ÷ 2 = 632 644 244 + 0;
- 632 644 244 ÷ 2 = 316 322 122 + 0;
- 316 322 122 ÷ 2 = 158 161 061 + 0;
- 158 161 061 ÷ 2 = 79 080 530 + 1;
- 79 080 530 ÷ 2 = 39 540 265 + 0;
- 39 540 265 ÷ 2 = 19 770 132 + 1;
- 19 770 132 ÷ 2 = 9 885 066 + 0;
- 9 885 066 ÷ 2 = 4 942 533 + 0;
- 4 942 533 ÷ 2 = 2 471 266 + 1;
- 2 471 266 ÷ 2 = 1 235 633 + 0;
- 1 235 633 ÷ 2 = 617 816 + 1;
- 617 816 ÷ 2 = 308 908 + 0;
- 308 908 ÷ 2 = 154 454 + 0;
- 154 454 ÷ 2 = 77 227 + 0;
- 77 227 ÷ 2 = 38 613 + 1;
- 38 613 ÷ 2 = 19 306 + 1;
- 19 306 ÷ 2 = 9 653 + 0;
- 9 653 ÷ 2 = 4 826 + 1;
- 4 826 ÷ 2 = 2 413 + 0;
- 2 413 ÷ 2 = 1 206 + 1;
- 1 206 ÷ 2 = 603 + 0;
- 603 ÷ 2 = 301 + 1;
- 301 ÷ 2 = 150 + 1;
- 150 ÷ 2 = 75 + 0;
- 75 ÷ 2 = 37 + 1;
- 37 ÷ 2 = 18 + 1;
- 18 ÷ 2 = 9 + 0;
- 9 ÷ 2 = 4 + 1;
- 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.
80 978 463 292(10) = 1 0010 1101 1010 1011 0001 0100 1010 0011 1100(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) 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, 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:
80 978 463 292(10) = 0000 0000 0000 0000 0000 0000 0001 0010 1101 1010 1011 0001 0100 1010 0011 1100
6. Get the negative integer number representation:
To get the negative integer number representation on 64 bits (8 Bytes),
... change the first bit (the leftmost), from 0 to 1...
-80 978 463 292(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-80 978 463 292(10) = 1000 0000 0000 0000 0000 0000 0001 0010 1101 1010 1011 0001 0100 1010 0011 1100
Spaces were used to group digits: for binary, by 4, for decimal, by 3.