1 - 111 0101 0111 - 1100 1011 1010 0000 0000 0000 0000 0000 0000 0000 0000 0001 1101 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard Converted to Decimal
1 - 111 0101 0111 - 1100 1011 1010 0000 0000 0000 0000 0000 0000 0000 0000 0001 1101: 64 bit double precision IEEE 754 binary floating point representation standard converted to decimal
What are the steps to convert
1 - 111 0101 0111 - 1100 1011 1010 0000 0000 0000 0000 0000 0000 0000 0000 0001 1101, 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:
111 0101 0111
The last 52 bits contain the mantissa:
1100 1011 1010 0000 0000 0000 0000 0000 0000 0000 0000 0001 1101
2. Convert the exponent from binary (from base 2) to decimal (in base 10).
The exponent is allways a positive integer.
111 0101 0111(2) =
1 × 210 + 1 × 29 + 1 × 28 + 0 × 27 + 1 × 26 + 0 × 25 + 1 × 24 + 0 × 23 + 1 × 22 + 1 × 21 + 1 × 20 =
1,024 + 512 + 256 + 0 + 64 + 0 + 16 + 0 + 4 + 2 + 1 =
1,024 + 512 + 256 + 64 + 16 + 4 + 2 + 1 =
1,879(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 = 1,879 - 1023 = 856
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 1011 1010 0000 0000 0000 0000 0000 0000 0000 0000 0001 1101(2) =
1 × 2-1 + 1 × 2-2 + 0 × 2-3 + 0 × 2-4 + 1 × 2-5 + 0 × 2-6 + 1 × 2-7 + 1 × 2-8 + 1 × 2-9 + 0 × 2-10 + 1 × 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 + 1 × 2-48 + 1 × 2-49 + 1 × 2-50 + 0 × 2-51 + 1 × 2-52 =
0.5 + 0.25 + 0 + 0 + 0.031 25 + 0 + 0.007 812 5 + 0.003 906 25 + 0.001 953 125 + 0 + 0.000 488 281 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 + 0.000 000 000 000 003 552 713 678 800 500 929 355 621 337 890 625 + 0.000 000 000 000 001 776 356 839 400 250 464 677 810 668 945 312 5 + 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 =
0.5 + 0.25 + 0.031 25 + 0.007 812 5 + 0.003 906 25 + 0.001 953 125 + 0.000 488 281 25 + 0.000 000 000 000 003 552 713 678 800 500 929 355 621 337 890 625 + 0.000 000 000 000 001 776 356 839 400 250 464 677 810 668 945 312 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 =
0.795 410 156 250 006 439 293 542 825 907 934 457 063 674 926 757 812 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)1 × (1 + 0.795 410 156 250 006 439 293 542 825 907 934 457 063 674 926 757 812 5) × 2856 =
-1.795 410 156 250 006 439 293 542 825 907 934 457 063 674 926 757 812 5 × 2856 = ...
= -862 660 605 609 843 179 758 820 195 201 993 719 271 335 270 459 915 515 929 256 431 451 205 056 855 840 751 954 610 450 511 902 388 675 170 364 668 133 466 783 563 976 402 398 359 032 200 745 378 688 988 890 893 023 153 204 102 287 430 203 845 832 204 741 902 717 338 289 023 972 876 313 507 572 236 611 290 367 588 928 558 664 119 356 489 728
1 - 111 0101 0111 - 1100 1011 1010 0000 0000 0000 0000 0000 0000 0000 0000 0001 1101, a 64 bit double precision IEEE 754 binary floating point representation standard to a decimal number, written in base ten (double) = -862 660 605 609 843 179 758 820 195 201 993 719 271 335 270 459 915 515 929 256 431 451 205 056 855 840 751 954 610 450 511 902 388 675 170 364 668 133 466 783 563 976 402 398 359 032 200 745 378 688 988 890 893 023 153 204 102 287 430 203 845 832 204 741 902 717 338 289 023 972 876 313 507 572 236 611 290 367 588 928 558 664 119 356 489 728(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.