What are the required steps to convert base 10 integer
number 1 991 276 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;
- 1 991 276 ÷ 2 = 995 638 + 0;
- 995 638 ÷ 2 = 497 819 + 0;
- 497 819 ÷ 2 = 248 909 + 1;
- 248 909 ÷ 2 = 124 454 + 1;
- 124 454 ÷ 2 = 62 227 + 0;
- 62 227 ÷ 2 = 31 113 + 1;
- 31 113 ÷ 2 = 15 556 + 1;
- 15 556 ÷ 2 = 7 778 + 0;
- 7 778 ÷ 2 = 3 889 + 0;
- 3 889 ÷ 2 = 1 944 + 1;
- 1 944 ÷ 2 = 972 + 0;
- 972 ÷ 2 = 486 + 0;
- 486 ÷ 2 = 243 + 0;
- 243 ÷ 2 = 121 + 1;
- 121 ÷ 2 = 60 + 1;
- 60 ÷ 2 = 30 + 0;
- 30 ÷ 2 = 15 + 0;
- 15 ÷ 2 = 7 + 1;
- 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.
1 991 276(10) = 1 1110 0110 0010 0110 1100(2)
3. Determine the signed binary number bit length:
The base 2 number's actual length, in bits: 21.
- 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, 21,
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:
1 991 276(10) Base 10 integer number converted and written as a signed binary code (in base 2):
1 991 276(10) = 0000 0000 0001 1110 0110 0010 0110 1100
Spaces were used to group digits: for binary, by 4, for decimal, by 3.