What are the required steps to convert base 10 integer
number -2 841 149 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:
|-2 841 149| = 2 841 149
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;
- 2 841 149 ÷ 2 = 1 420 574 + 1;
- 1 420 574 ÷ 2 = 710 287 + 0;
- 710 287 ÷ 2 = 355 143 + 1;
- 355 143 ÷ 2 = 177 571 + 1;
- 177 571 ÷ 2 = 88 785 + 1;
- 88 785 ÷ 2 = 44 392 + 1;
- 44 392 ÷ 2 = 22 196 + 0;
- 22 196 ÷ 2 = 11 098 + 0;
- 11 098 ÷ 2 = 5 549 + 0;
- 5 549 ÷ 2 = 2 774 + 1;
- 2 774 ÷ 2 = 1 387 + 0;
- 1 387 ÷ 2 = 693 + 1;
- 693 ÷ 2 = 346 + 1;
- 346 ÷ 2 = 173 + 0;
- 173 ÷ 2 = 86 + 1;
- 86 ÷ 2 = 43 + 0;
- 43 ÷ 2 = 21 + 1;
- 21 ÷ 2 = 10 + 1;
- 10 ÷ 2 = 5 + 0;
- 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.
2 841 149(10) = 10 1011 0101 1010 0011 1101(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 22.
- 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, 22,
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:
2 841 149(10) = 0000 0000 0010 1011 0101 1010 0011 1101
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...
-2 841 149(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-2 841 149(10) = 1000 0000 0010 1011 0101 1010 0011 1101
Spaces were used to group digits: for binary, by 4, for decimal, by 3.