1 - 111 1001 0101 - 1011 1111 1100 0110 0001 0000 1111 0110 0000 0000 0000 0101 1000 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard Converted to Decimal
1 - 111 1001 0101 - 1011 1111 1100 0110 0001 0000 1111 0110 0000 0000 0000 0101 1000: 64 bit double precision IEEE 754 binary floating point representation standard converted to decimal
What are the steps to convert
1 - 111 1001 0101 - 1011 1111 1100 0110 0001 0000 1111 0110 0000 0000 0000 0101 1000, 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 1001 0101
The last 52 bits contain the mantissa:
1011 1111 1100 0110 0001 0000 1111 0110 0000 0000 0000 0101 1000
2. Convert the exponent from binary (from base 2) to decimal (in base 10).
The exponent is allways a positive integer.
111 1001 0101(2) =
1 × 210 + 1 × 29 + 1 × 28 + 1 × 27 + 0 × 26 + 0 × 25 + 1 × 24 + 0 × 23 + 1 × 22 + 0 × 21 + 1 × 20 =
1,024 + 512 + 256 + 128 + 0 + 0 + 16 + 0 + 4 + 0 + 1 =
1,024 + 512 + 256 + 128 + 16 + 4 + 1 =
1,941(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 = 1,941 - 1023 = 918
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).
1011 1111 1100 0110 0001 0000 1111 0110 0000 0000 0000 0101 1000(2) =
1 × 2-1 + 0 × 2-2 + 1 × 2-3 + 1 × 2-4 + 1 × 2-5 + 1 × 2-6 + 1 × 2-7 + 1 × 2-8 + 1 × 2-9 + 1 × 2-10 + 0 × 2-11 + 0 × 2-12 + 0 × 2-13 + 1 × 2-14 + 1 × 2-15 + 0 × 2-16 + 0 × 2-17 + 0 × 2-18 + 0 × 2-19 + 1 × 2-20 + 0 × 2-21 + 0 × 2-22 + 0 × 2-23 + 0 × 2-24 + 1 × 2-25 + 1 × 2-26 + 1 × 2-27 + 1 × 2-28 + 0 × 2-29 + 1 × 2-30 + 1 × 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 + 1 × 2-46 + 0 × 2-47 + 1 × 2-48 + 1 × 2-49 + 0 × 2-50 + 0 × 2-51 + 0 × 2-52 =
0.5 + 0 + 0.125 + 0.062 5 + 0.031 25 + 0.015 625 + 0.007 812 5 + 0.003 906 25 + 0.001 953 125 + 0.000 976 562 5 + 0 + 0 + 0 + 0.000 061 035 156 25 + 0.000 030 517 578 125 + 0 + 0 + 0 + 0 + 0.000 000 953 674 316 406 25 + 0 + 0 + 0 + 0 + 0.000 000 029 802 322 387 695 312 5 + 0.000 000 014 901 161 193 847 656 25 + 0.000 000 007 450 580 596 923 828 125 + 0.000 000 003 725 290 298 461 914 062 5 + 0 + 0.000 000 000 931 322 574 615 478 515 625 + 0.000 000 000 465 661 287 307 739 257 812 5 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0.000 000 000 000 014 210 854 715 202 003 717 422 485 351 562 5 + 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 + 0 + 0 =
0.5 + 0.125 + 0.062 5 + 0.031 25 + 0.015 625 + 0.007 812 5 + 0.003 906 25 + 0.001 953 125 + 0.000 976 562 5 + 0.000 061 035 156 25 + 0.000 030 517 578 125 + 0.000 000 953 674 316 406 25 + 0.000 000 029 802 322 387 695 312 5 + 0.000 000 014 901 161 193 847 656 25 + 0.000 000 007 450 580 596 923 828 125 + 0.000 000 003 725 290 298 461 914 062 5 + 0.000 000 000 931 322 574 615 478 515 625 + 0.000 000 000 465 661 287 307 739 257 812 5 + 0.000 000 000 000 014 210 854 715 202 003 717 422 485 351 562 5 + 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 =
0.749 116 001 185 049 285 027 162 113 692 611 455 917 358 398 437 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 + 0.749 116 001 185 049 285 027 162 113 692 611 455 917 358 398 437 5) × 2918 =
-1.749 116 001 185 049 285 027 162 113 692 611 455 917 358 398 437 5 × 2918 = ...
= -3 875 739 974 753 878 003 185 978 030 858 672 676 158 154 729 240 710 618 030 722 124 851 927 964 688 098 883 228 837 090 811 509 348 360 384 110 441 750 246 599 814 095 462 430 887 007 886 758 580 531 264 079 126 566 977 101 586 279 924 408 804 514 037 358 857 892 625 796 687 269 709 498 277 349 193 966 030 603 095 549 399 627 563 647 659 015 448 504 503 516 528 640
1 - 111 1001 0101 - 1011 1111 1100 0110 0001 0000 1111 0110 0000 0000 0000 0101 1000, a 64 bit double precision IEEE 754 binary floating point representation standard to a decimal number, written in base ten (double) = -3 875 739 974 753 878 003 185 978 030 858 672 676 158 154 729 240 710 618 030 722 124 851 927 964 688 098 883 228 837 090 811 509 348 360 384 110 441 750 246 599 814 095 462 430 887 007 886 758 580 531 264 079 126 566 977 101 586 279 924 408 804 514 037 358 857 892 625 796 687 269 709 498 277 349 193 966 030 603 095 549 399 627 563 647 659 015 448 504 503 516 528 640(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.