What are the required steps to convert base 10 integer
number 121 142 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. 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;
- 121 142 ÷ 2 = 60 571 + 0;
- 60 571 ÷ 2 = 30 285 + 1;
- 30 285 ÷ 2 = 15 142 + 1;
- 15 142 ÷ 2 = 7 571 + 0;
- 7 571 ÷ 2 = 3 785 + 1;
- 3 785 ÷ 2 = 1 892 + 1;
- 1 892 ÷ 2 = 946 + 0;
- 946 ÷ 2 = 473 + 0;
- 473 ÷ 2 = 236 + 1;
- 236 ÷ 2 = 118 + 0;
- 118 ÷ 2 = 59 + 0;
- 59 ÷ 2 = 29 + 1;
- 29 ÷ 2 = 14 + 1;
- 14 ÷ 2 = 7 + 0;
- 7 ÷ 2 = 3 + 1;
- 3 ÷ 2 = 1 + 1;
- 1 ÷ 2 = 0 + 1;
2. Construct the base 2 representation of the positive number:
Take all the remainders starting from the bottom of the list constructed above.
121 142(10) = 1 1101 1001 0011 0110(2)
3. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 17.
- 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, 17,
3) so that the first bit (leftmost) could be zero
(we deal with a positive number at this moment)
=== is: 32.
4. 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:
121 142(10) Base 10 integer number converted and written as a signed binary code (in base 2):
121 142(10) = 0000 0000 0000 0001 1101 1001 0011 0110
Spaces were used to group digits: for binary, by 4, for decimal, by 3.