0 - 111 1110 1000 - 1000 1011 1011 1110 1001 0000 0000 0000 0000 0000 0000 0000 0010 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard Converted to Decimal
0 - 111 1110 1000 - 1000 1011 1011 1110 1001 0000 0000 0000 0000 0000 0000 0000 0010: 64 bit double precision IEEE 754 binary floating point representation standard converted to decimal
What are the steps to convert
0 - 111 1110 1000 - 1000 1011 1011 1110 1001 0000 0000 0000 0000 0000 0000 0000 0010, 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 1110 1000
The last 52 bits contain the mantissa:
1000 1011 1011 1110 1001 0000 0000 0000 0000 0000 0000 0000 0010
2. Convert the exponent from binary (from base 2) to decimal (in base 10).
The exponent is allways a positive integer.
111 1110 1000(2) =
1 × 210 + 1 × 29 + 1 × 28 + 1 × 27 + 1 × 26 + 1 × 25 + 0 × 24 + 1 × 23 + 0 × 22 + 0 × 21 + 0 × 20 =
1,024 + 512 + 256 + 128 + 64 + 32 + 0 + 8 + 0 + 0 + 0 =
1,024 + 512 + 256 + 128 + 64 + 32 + 8 =
2,024(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 = 2,024 - 1023 = 1001
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).
1000 1011 1011 1110 1001 0000 0000 0000 0000 0000 0000 0000 0010(2) =
1 × 2-1 + 0 × 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 + 1 × 2-12 + 1 × 2-13 + 1 × 2-14 + 1 × 2-15 + 0 × 2-16 + 1 × 2-17 + 0 × 2-18 + 0 × 2-19 + 1 × 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 + 1 × 2-51 + 0 × 2-52 =
0.5 + 0 + 0 + 0 + 0.031 25 + 0 + 0.007 812 5 + 0.003 906 25 + 0.001 953 125 + 0 + 0.000 488 281 25 + 0.000 244 140 625 + 0.000 122 070 312 5 + 0.000 061 035 156 25 + 0.000 030 517 578 125 + 0 + 0.000 007 629 394 531 25 + 0 + 0 + 0.000 000 953 674 316 406 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 + 0.000 000 000 000 000 444 089 209 850 062 616 169 452 667 236 328 125 + 0 =
0.5 + 0.031 25 + 0.007 812 5 + 0.003 906 25 + 0.001 953 125 + 0.000 488 281 25 + 0.000 244 140 625 + 0.000 122 070 312 5 + 0.000 061 035 156 25 + 0.000 030 517 578 125 + 0.000 007 629 394 531 25 + 0.000 000 953 674 316 406 25 + 0.000 000 000 000 000 444 089 209 850 062 616 169 452 667 236 328 125 =
0.545 876 502 990 723 100 339 209 850 062 616 169 452 667 236 328 125(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 + 0.545 876 502 990 723 100 339 209 850 062 616 169 452 667 236 328 125) × 21001 =
1.545 876 502 990 723 100 339 209 850 062 616 169 452 667 236 328 125 × 21001 = ...
= 33 128 399 572 031 346 357 927 798 977 464 580 325 261 841 877 654 049 358 125 757 830 632 876 370 005 554 024 594 311 717 062 304 414 610 297 823 398 942 550 500 650 267 691 177 284 165 329 848 691 302 730 463 578 239 638 266 772 606 317 894 476 332 736 933 370 722 052 760 905 357 629 878 420 093 696 777 684 477 139 295 395 970 950 522 859 389 018 002 202 553 990 312 908 605 586 249 077 816 819 712
0 - 111 1110 1000 - 1000 1011 1011 1110 1001 0000 0000 0000 0000 0000 0000 0000 0010, a 64 bit double precision IEEE 754 binary floating point representation standard to a decimal number, written in base ten (double) = 33 128 399 572 031 346 357 927 798 977 464 580 325 261 841 877 654 049 358 125 757 830 632 876 370 005 554 024 594 311 717 062 304 414 610 297 823 398 942 550 500 650 267 691 177 284 165 329 848 691 302 730 463 578 239 638 266 772 606 317 894 476 332 736 933 370 722 052 760 905 357 629 878 420 093 696 777 684 477 139 295 395 970 950 522 859 389 018 002 202 553 990 312 908 605 586 249 077 816 819 712(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.