What are the steps to convert
1 - 101 1111 0000 - 1100 1000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000, a 64 bit double precision IEEE 754 binary floating point representation standard to decimal?
1. Identify the elements that make up the binary representation of the number:
The first bit (the leftmost) indicates the sign,
1 = negative, 0 = positive.
1
The next 11 bits contain the exponent:
101 1111 0000
The last 52 bits contain the mantissa:
1100 1000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000
2. Convert the exponent from binary (from base 2) to decimal (in base 10).
The exponent is allways a positive integer.
101 1111 0000(2) =
1 × 210 + 0 × 29 + 1 × 28 + 1 × 27 + 1 × 26 + 1 × 25 + 1 × 24 + 0 × 23 + 0 × 22 + 0 × 21 + 0 × 20 =
1,024 + 0 + 256 + 128 + 64 + 32 + 16 + 0 + 0 + 0 + 0 =
1,024 + 256 + 128 + 64 + 32 + 16 =
1,520(10)
3. Adjust the exponent.
Subtract the excess bits: 2(11 - 1) - 1 = 1023,
that is due to the 11 bit excess/bias notation.
The exponent, adjusted = 1,520 - 1023 = 497
4. Convert the mantissa from binary (from base 2) to decimal (in base 10).
The mantissa represents the fractional part of the number (what comes after the whole part of the number, separated from it by a comma).
1100 1000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000(2) =
1 × 2-1 + 1 × 2-2 + 0 × 2-3 + 0 × 2-4 + 1 × 2-5 + 0 × 2-6 + 0 × 2-7 + 0 × 2-8 + 0 × 2-9 + 0 × 2-10 + 0 × 2-11 + 0 × 2-12 + 0 × 2-13 + 0 × 2-14 + 0 × 2-15 + 0 × 2-16 + 0 × 2-17 + 0 × 2-18 + 0 × 2-19 + 0 × 2-20 + 0 × 2-21 + 0 × 2-22 + 0 × 2-23 + 0 × 2-24 + 0 × 2-25 + 0 × 2-26 + 0 × 2-27 + 0 × 2-28 + 0 × 2-29 + 0 × 2-30 + 0 × 2-31 + 0 × 2-32 + 0 × 2-33 + 0 × 2-34 + 0 × 2-35 + 0 × 2-36 + 0 × 2-37 + 0 × 2-38 + 0 × 2-39 + 0 × 2-40 + 0 × 2-41 + 0 × 2-42 + 0 × 2-43 + 0 × 2-44 + 0 × 2-45 + 0 × 2-46 + 0 × 2-47 + 0 × 2-48 + 0 × 2-49 + 0 × 2-50 + 0 × 2-51 + 0 × 2-52 =
0.5 + 0.25 + 0 + 0 + 0.031 25 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 =
0.5 + 0.25 + 0.031 25 =
0.781 25(10)
= -728 840 877 539 375 338 245 124 268 434 270 123 735 736 705 564 276 144 533 389 093 677 654 790 605 728 318 860 728 106 494 439 597 490 627 113 262 777 047 060 646 029 777 794 794 547 030 179 971 072
1 - 101 1111 0000 - 1100 1000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000, a 64 bit double precision IEEE 754 binary floating point representation standard to a decimal number, written in base ten (double) = -728 840 877 539 375 338 245 124 268 434 270 123 735 736 705 564 276 144 533 389 093 677 654 790 605 728 318 860 728 106 494 439 597 490 627 113 262 777 047 060 646 029 777 794 794 547 030 179 971 072(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.