What are the required steps to convert base 10 integer
number -1 241 513 688 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:
|-1 241 513 688| = 1 241 513 688
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;
- 1 241 513 688 ÷ 2 = 620 756 844 + 0;
- 620 756 844 ÷ 2 = 310 378 422 + 0;
- 310 378 422 ÷ 2 = 155 189 211 + 0;
- 155 189 211 ÷ 2 = 77 594 605 + 1;
- 77 594 605 ÷ 2 = 38 797 302 + 1;
- 38 797 302 ÷ 2 = 19 398 651 + 0;
- 19 398 651 ÷ 2 = 9 699 325 + 1;
- 9 699 325 ÷ 2 = 4 849 662 + 1;
- 4 849 662 ÷ 2 = 2 424 831 + 0;
- 2 424 831 ÷ 2 = 1 212 415 + 1;
- 1 212 415 ÷ 2 = 606 207 + 1;
- 606 207 ÷ 2 = 303 103 + 1;
- 303 103 ÷ 2 = 151 551 + 1;
- 151 551 ÷ 2 = 75 775 + 1;
- 75 775 ÷ 2 = 37 887 + 1;
- 37 887 ÷ 2 = 18 943 + 1;
- 18 943 ÷ 2 = 9 471 + 1;
- 9 471 ÷ 2 = 4 735 + 1;
- 4 735 ÷ 2 = 2 367 + 1;
- 2 367 ÷ 2 = 1 183 + 1;
- 1 183 ÷ 2 = 591 + 1;
- 591 ÷ 2 = 295 + 1;
- 295 ÷ 2 = 147 + 1;
- 147 ÷ 2 = 73 + 1;
- 73 ÷ 2 = 36 + 1;
- 36 ÷ 2 = 18 + 0;
- 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.
1 241 513 688(10) = 100 1001 1111 1111 1111 1110 1101 1000(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:
1 241 513 688(10) = 0100 1001 1111 1111 1111 1110 1101 1000
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...
-1 241 513 688(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-1 241 513 688(10) = 1100 1001 1111 1111 1111 1110 1101 1000
Spaces were used to group digits: for binary, by 4, for decimal, by 3.