0 - 111 1111 1000 - 0011 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0101 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard Converted to Decimal
0 - 111 1111 1000 - 0011 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0101: 64 bit double precision IEEE 754 binary floating point representation standard converted to decimal
What are the steps to convert
0 - 111 1111 1000 - 0011 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0101, 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.
0
The next 11 bits contain the exponent:
111 1111 1000
The last 52 bits contain the mantissa:
0011 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0101
2. Convert the exponent from binary (from base 2) to decimal (in base 10).
The exponent is allways a positive integer.
111 1111 1000(2) =
1 × 210 + 1 × 29 + 1 × 28 + 1 × 27 + 1 × 26 + 1 × 25 + 1 × 24 + 1 × 23 + 0 × 22 + 0 × 21 + 0 × 20 =
1,024 + 512 + 256 + 128 + 64 + 32 + 16 + 8 + 0 + 0 + 0 =
1,024 + 512 + 256 + 128 + 64 + 32 + 16 + 8 =
2,040(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 = 2,040 - 1023 = 1017
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).
0011 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0101(2) =
0 × 2-1 + 0 × 2-2 + 1 × 2-3 + 1 × 2-4 + 0 × 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 + 1 × 2-50 + 0 × 2-51 + 1 × 2-52 =
0 + 0 + 0.125 + 0.062 5 + 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 + 0.000 000 000 000 000 888 178 419 700 125 232 338 905 334 472 656 25 + 0 + 0.000 000 000 000 000 222 044 604 925 031 308 084 726 333 618 164 062 5 =
0.125 + 0.062 5 + 0.000 000 000 000 000 888 178 419 700 125 232 338 905 334 472 656 25 + 0.000 000 000 000 000 222 044 604 925 031 308 084 726 333 618 164 062 5 =
0.187 500 000 000 001 110 223 024 625 156 540 423 631 668 090 820 312 5(10)
5. Put all the numbers into expression to calculate the double precision floating point decimal value:
(-1)Sign × (1 + Mantissa) × 2(Adjusted exponent) =
(-1)0 × (1 + 0.187 500 000 000 001 110 223 024 625 156 540 423 631 668 090 820 312 5) × 21017 =
1.187 500 000 000 001 110 223 024 625 156 540 423 631 668 090 820 312 5 × 21017 = ...
= 1 667 781 716 913 282 918 960 046 444 360 764 474 643 797 421 353 558 689 510 345 819 691 888 302 919 973 730 010 003 935 287 230 683 756 849 097 624 354 598 019 253 884 919 661 282 316 047 305 962 841 731 223 560 775 015 040 389 029 423 251 413 164 432 722 817 364 690 952 341 114 186 179 518 669 328 703 162 744 666 647 298 994 007 945 356 064 393 452 967 750 219 079 121 475 213 655 011 786 529 919 991 808
0 - 111 1111 1000 - 0011 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0101, a 64 bit double precision IEEE 754 binary floating point representation standard to a decimal number, written in base ten (double) = 1 667 781 716 913 282 918 960 046 444 360 764 474 643 797 421 353 558 689 510 345 819 691 888 302 919 973 730 010 003 935 287 230 683 756 849 097 624 354 598 019 253 884 919 661 282 316 047 305 962 841 731 223 560 775 015 040 389 029 423 251 413 164 432 722 817 364 690 952 341 114 186 179 518 669 328 703 162 744 666 647 298 994 007 945 356 064 393 452 967 750 219 079 121 475 213 655 011 786 529 919 991 808(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.