What are the required steps to convert base 10 integer
number -140 189 562 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:
|-140 189 562| = 140 189 562
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;
- 140 189 562 ÷ 2 = 70 094 781 + 0;
- 70 094 781 ÷ 2 = 35 047 390 + 1;
- 35 047 390 ÷ 2 = 17 523 695 + 0;
- 17 523 695 ÷ 2 = 8 761 847 + 1;
- 8 761 847 ÷ 2 = 4 380 923 + 1;
- 4 380 923 ÷ 2 = 2 190 461 + 1;
- 2 190 461 ÷ 2 = 1 095 230 + 1;
- 1 095 230 ÷ 2 = 547 615 + 0;
- 547 615 ÷ 2 = 273 807 + 1;
- 273 807 ÷ 2 = 136 903 + 1;
- 136 903 ÷ 2 = 68 451 + 1;
- 68 451 ÷ 2 = 34 225 + 1;
- 34 225 ÷ 2 = 17 112 + 1;
- 17 112 ÷ 2 = 8 556 + 0;
- 8 556 ÷ 2 = 4 278 + 0;
- 4 278 ÷ 2 = 2 139 + 0;
- 2 139 ÷ 2 = 1 069 + 1;
- 1 069 ÷ 2 = 534 + 1;
- 534 ÷ 2 = 267 + 0;
- 267 ÷ 2 = 133 + 1;
- 133 ÷ 2 = 66 + 1;
- 66 ÷ 2 = 33 + 0;
- 33 ÷ 2 = 16 + 1;
- 16 ÷ 2 = 8 + 0;
- 8 ÷ 2 = 4 + 0;
- 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.
140 189 562(10) = 1000 0101 1011 0001 1111 0111 1010(2)
4. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 28.
- 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, 28,
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:
140 189 562(10) = 0000 1000 0101 1011 0001 1111 0111 1010
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...
-140 189 562(10) Base 10 integer number converted and written as a signed binary code (in base 2):
-140 189 562(10) = 1000 1000 0101 1011 0001 1111 0111 1010
Spaces were used to group digits: for binary, by 4, for decimal, by 3.