What are the required steps to convert base 10 integer
number 72 145 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;
- 72 145 ÷ 2 = 36 072 + 1;
- 36 072 ÷ 2 = 18 036 + 0;
- 18 036 ÷ 2 = 9 018 + 0;
- 9 018 ÷ 2 = 4 509 + 0;
- 4 509 ÷ 2 = 2 254 + 1;
- 2 254 ÷ 2 = 1 127 + 0;
- 1 127 ÷ 2 = 563 + 1;
- 563 ÷ 2 = 281 + 1;
- 281 ÷ 2 = 140 + 1;
- 140 ÷ 2 = 70 + 0;
- 70 ÷ 2 = 35 + 0;
- 35 ÷ 2 = 17 + 1;
- 17 ÷ 2 = 8 + 1;
- 8 ÷ 2 = 4 + 0;
- 4 ÷ 2 = 2 + 0;
- 2 ÷ 2 = 1 + 0;
- 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.
72 145(10) = 1 0001 1001 1101 0001(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:
72 145(10) Base 10 integer number converted and written as a signed binary code (in base 2):
72 145(10) = 0000 0000 0000 0001 0001 1001 1101 0001
Spaces were used to group digits: for binary, by 4, for decimal, by 3.