1 - 111 1111 1000 - 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0010 0100 0101 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard Converted to Decimal
1 - 111 1111 1000 - 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0010 0100 0101: 64 bit double precision IEEE 754 binary floating point representation standard converted to decimal
What are the steps to convert
1 - 111 1111 1000 - 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0010 0100 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.
1
The next 11 bits contain the exponent:
111 1111 1000
The last 52 bits contain the mantissa:
0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0010 0100 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).
0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0010 0100 0101(2) =
0 × 2-1 + 0 × 2-2 + 0 × 2-3 + 0 × 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 + 1 × 2-43 + 0 × 2-44 + 0 × 2-45 + 1 × 2-46 + 0 × 2-47 + 0 × 2-48 + 0 × 2-49 + 1 × 2-50 + 0 × 2-51 + 1 × 2-52 =
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 + 0.000 000 000 000 113 686 837 721 616 029 739 379 882 812 5 + 0 + 0 + 0.000 000 000 000 014 210 854 715 202 003 717 422 485 351 562 5 + 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 =
0.000 000 000 000 113 686 837 721 616 029 739 379 882 812 5 + 0.000 000 000 000 014 210 854 715 202 003 717 422 485 351 562 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 =
0.000 000 000 000 129 007 915 461 443 189 997 225 999 832 153 320 312 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)1 × (1 + 0.000 000 000 000 129 007 915 461 443 189 997 225 999 832 153 320 312 5) × 21017 =
-1.000 000 000 000 129 007 915 461 443 189 997 225 999 832 153 320 312 5 × 21017 = ...
= -1 404 447 761 611 365 487 791 619 629 086 827 503 224 399 890 299 752 820 758 408 915 424 726 057 847 328 777 616 343 708 475 405 915 880 305 768 021 234 777 475 711 869 418 821 496 736 111 504 407 795 405 574 641 124 712 234 137 529 236 108 681 381 306 468 029 502 081 640 594 282 819 090 017 833 900 510 824 151 575 117 615 204 106 731 014 663 732 004 148 319 415 173 622 528 128 988 671 350 992 340 516 864
1 - 111 1111 1000 - 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0010 0100 0101, a 64 bit double precision IEEE 754 binary floating point representation standard to a decimal number, written in base ten (double) = -1 404 447 761 611 365 487 791 619 629 086 827 503 224 399 890 299 752 820 758 408 915 424 726 057 847 328 777 616 343 708 475 405 915 880 305 768 021 234 777 475 711 869 418 821 496 736 111 504 407 795 405 574 641 124 712 234 137 529 236 108 681 381 306 468 029 502 081 640 594 282 819 090 017 833 900 510 824 151 575 117 615 204 106 731 014 663 732 004 148 319 415 173 622 528 128 988 671 350 992 340 516 864(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.