-0.000 806 264 623 585 362 514 063 654 156 856 105 034 342 553 933 4 Converted to 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard

Convert decimal -0.000 806 264 623 585 362 514 063 654 156 856 105 034 342 553 933 4(10) to 64 bit double precision IEEE 754 binary floating point representation standard (1 bit for sign, 11 bits for exponent, 52 bits for mantissa)

What are the steps to convert decimal number
-0.000 806 264 623 585 362 514 063 654 156 856 105 034 342 553 933 4(10) to 64 bit double precision IEEE 754 binary floating point representation (1 bit for sign, 11 bits for exponent, 52 bits for mantissa)

1. Start with the positive version of the number:

|-0.000 806 264 623 585 362 514 063 654 156 856 105 034 342 553 933 4| = 0.000 806 264 623 585 362 514 063 654 156 856 105 034 342 553 933 4


2. First, convert to binary (in base 2) the integer part: 0.
Divide the number repeatedly by 2.

Keep track of each remainder.

We stop when we get a quotient that is equal to zero.


  • division = quotient + remainder;
  • 0 ÷ 2 = 0 + 0;

3. Construct the base 2 representation of the integer part of the number.

Take all the remainders starting from the bottom of the list constructed above.

0(10) =


0(2)


4. Convert to binary (base 2) the fractional part: 0.000 806 264 623 585 362 514 063 654 156 856 105 034 342 553 933 4.

Multiply it repeatedly by 2.


Keep track of each integer part of the results.


Stop when we get a fractional part that is equal to zero.


  • #) multiplying = integer + fractional part;
  • 1) 0.000 806 264 623 585 362 514 063 654 156 856 105 034 342 553 933 4 × 2 = 0 + 0.001 612 529 247 170 725 028 127 308 313 712 210 068 685 107 866 8;
  • 2) 0.001 612 529 247 170 725 028 127 308 313 712 210 068 685 107 866 8 × 2 = 0 + 0.003 225 058 494 341 450 056 254 616 627 424 420 137 370 215 733 6;
  • 3) 0.003 225 058 494 341 450 056 254 616 627 424 420 137 370 215 733 6 × 2 = 0 + 0.006 450 116 988 682 900 112 509 233 254 848 840 274 740 431 467 2;
  • 4) 0.006 450 116 988 682 900 112 509 233 254 848 840 274 740 431 467 2 × 2 = 0 + 0.012 900 233 977 365 800 225 018 466 509 697 680 549 480 862 934 4;
  • 5) 0.012 900 233 977 365 800 225 018 466 509 697 680 549 480 862 934 4 × 2 = 0 + 0.025 800 467 954 731 600 450 036 933 019 395 361 098 961 725 868 8;
  • 6) 0.025 800 467 954 731 600 450 036 933 019 395 361 098 961 725 868 8 × 2 = 0 + 0.051 600 935 909 463 200 900 073 866 038 790 722 197 923 451 737 6;
  • 7) 0.051 600 935 909 463 200 900 073 866 038 790 722 197 923 451 737 6 × 2 = 0 + 0.103 201 871 818 926 401 800 147 732 077 581 444 395 846 903 475 2;
  • 8) 0.103 201 871 818 926 401 800 147 732 077 581 444 395 846 903 475 2 × 2 = 0 + 0.206 403 743 637 852 803 600 295 464 155 162 888 791 693 806 950 4;
  • 9) 0.206 403 743 637 852 803 600 295 464 155 162 888 791 693 806 950 4 × 2 = 0 + 0.412 807 487 275 705 607 200 590 928 310 325 777 583 387 613 900 8;
  • 10) 0.412 807 487 275 705 607 200 590 928 310 325 777 583 387 613 900 8 × 2 = 0 + 0.825 614 974 551 411 214 401 181 856 620 651 555 166 775 227 801 6;
  • 11) 0.825 614 974 551 411 214 401 181 856 620 651 555 166 775 227 801 6 × 2 = 1 + 0.651 229 949 102 822 428 802 363 713 241 303 110 333 550 455 603 2;
  • 12) 0.651 229 949 102 822 428 802 363 713 241 303 110 333 550 455 603 2 × 2 = 1 + 0.302 459 898 205 644 857 604 727 426 482 606 220 667 100 911 206 4;
  • 13) 0.302 459 898 205 644 857 604 727 426 482 606 220 667 100 911 206 4 × 2 = 0 + 0.604 919 796 411 289 715 209 454 852 965 212 441 334 201 822 412 8;
  • 14) 0.604 919 796 411 289 715 209 454 852 965 212 441 334 201 822 412 8 × 2 = 1 + 0.209 839 592 822 579 430 418 909 705 930 424 882 668 403 644 825 6;
  • 15) 0.209 839 592 822 579 430 418 909 705 930 424 882 668 403 644 825 6 × 2 = 0 + 0.419 679 185 645 158 860 837 819 411 860 849 765 336 807 289 651 2;
  • 16) 0.419 679 185 645 158 860 837 819 411 860 849 765 336 807 289 651 2 × 2 = 0 + 0.839 358 371 290 317 721 675 638 823 721 699 530 673 614 579 302 4;
  • 17) 0.839 358 371 290 317 721 675 638 823 721 699 530 673 614 579 302 4 × 2 = 1 + 0.678 716 742 580 635 443 351 277 647 443 399 061 347 229 158 604 8;
  • 18) 0.678 716 742 580 635 443 351 277 647 443 399 061 347 229 158 604 8 × 2 = 1 + 0.357 433 485 161 270 886 702 555 294 886 798 122 694 458 317 209 6;
  • 19) 0.357 433 485 161 270 886 702 555 294 886 798 122 694 458 317 209 6 × 2 = 0 + 0.714 866 970 322 541 773 405 110 589 773 596 245 388 916 634 419 2;
  • 20) 0.714 866 970 322 541 773 405 110 589 773 596 245 388 916 634 419 2 × 2 = 1 + 0.429 733 940 645 083 546 810 221 179 547 192 490 777 833 268 838 4;
  • 21) 0.429 733 940 645 083 546 810 221 179 547 192 490 777 833 268 838 4 × 2 = 0 + 0.859 467 881 290 167 093 620 442 359 094 384 981 555 666 537 676 8;
  • 22) 0.859 467 881 290 167 093 620 442 359 094 384 981 555 666 537 676 8 × 2 = 1 + 0.718 935 762 580 334 187 240 884 718 188 769 963 111 333 075 353 6;
  • 23) 0.718 935 762 580 334 187 240 884 718 188 769 963 111 333 075 353 6 × 2 = 1 + 0.437 871 525 160 668 374 481 769 436 377 539 926 222 666 150 707 2;
  • 24) 0.437 871 525 160 668 374 481 769 436 377 539 926 222 666 150 707 2 × 2 = 0 + 0.875 743 050 321 336 748 963 538 872 755 079 852 445 332 301 414 4;
  • 25) 0.875 743 050 321 336 748 963 538 872 755 079 852 445 332 301 414 4 × 2 = 1 + 0.751 486 100 642 673 497 927 077 745 510 159 704 890 664 602 828 8;
  • 26) 0.751 486 100 642 673 497 927 077 745 510 159 704 890 664 602 828 8 × 2 = 1 + 0.502 972 201 285 346 995 854 155 491 020 319 409 781 329 205 657 6;
  • 27) 0.502 972 201 285 346 995 854 155 491 020 319 409 781 329 205 657 6 × 2 = 1 + 0.005 944 402 570 693 991 708 310 982 040 638 819 562 658 411 315 2;
  • 28) 0.005 944 402 570 693 991 708 310 982 040 638 819 562 658 411 315 2 × 2 = 0 + 0.011 888 805 141 387 983 416 621 964 081 277 639 125 316 822 630 4;
  • 29) 0.011 888 805 141 387 983 416 621 964 081 277 639 125 316 822 630 4 × 2 = 0 + 0.023 777 610 282 775 966 833 243 928 162 555 278 250 633 645 260 8;
  • 30) 0.023 777 610 282 775 966 833 243 928 162 555 278 250 633 645 260 8 × 2 = 0 + 0.047 555 220 565 551 933 666 487 856 325 110 556 501 267 290 521 6;
  • 31) 0.047 555 220 565 551 933 666 487 856 325 110 556 501 267 290 521 6 × 2 = 0 + 0.095 110 441 131 103 867 332 975 712 650 221 113 002 534 581 043 2;
  • 32) 0.095 110 441 131 103 867 332 975 712 650 221 113 002 534 581 043 2 × 2 = 0 + 0.190 220 882 262 207 734 665 951 425 300 442 226 005 069 162 086 4;
  • 33) 0.190 220 882 262 207 734 665 951 425 300 442 226 005 069 162 086 4 × 2 = 0 + 0.380 441 764 524 415 469 331 902 850 600 884 452 010 138 324 172 8;
  • 34) 0.380 441 764 524 415 469 331 902 850 600 884 452 010 138 324 172 8 × 2 = 0 + 0.760 883 529 048 830 938 663 805 701 201 768 904 020 276 648 345 6;
  • 35) 0.760 883 529 048 830 938 663 805 701 201 768 904 020 276 648 345 6 × 2 = 1 + 0.521 767 058 097 661 877 327 611 402 403 537 808 040 553 296 691 2;
  • 36) 0.521 767 058 097 661 877 327 611 402 403 537 808 040 553 296 691 2 × 2 = 1 + 0.043 534 116 195 323 754 655 222 804 807 075 616 081 106 593 382 4;
  • 37) 0.043 534 116 195 323 754 655 222 804 807 075 616 081 106 593 382 4 × 2 = 0 + 0.087 068 232 390 647 509 310 445 609 614 151 232 162 213 186 764 8;
  • 38) 0.087 068 232 390 647 509 310 445 609 614 151 232 162 213 186 764 8 × 2 = 0 + 0.174 136 464 781 295 018 620 891 219 228 302 464 324 426 373 529 6;
  • 39) 0.174 136 464 781 295 018 620 891 219 228 302 464 324 426 373 529 6 × 2 = 0 + 0.348 272 929 562 590 037 241 782 438 456 604 928 648 852 747 059 2;
  • 40) 0.348 272 929 562 590 037 241 782 438 456 604 928 648 852 747 059 2 × 2 = 0 + 0.696 545 859 125 180 074 483 564 876 913 209 857 297 705 494 118 4;
  • 41) 0.696 545 859 125 180 074 483 564 876 913 209 857 297 705 494 118 4 × 2 = 1 + 0.393 091 718 250 360 148 967 129 753 826 419 714 595 410 988 236 8;
  • 42) 0.393 091 718 250 360 148 967 129 753 826 419 714 595 410 988 236 8 × 2 = 0 + 0.786 183 436 500 720 297 934 259 507 652 839 429 190 821 976 473 6;
  • 43) 0.786 183 436 500 720 297 934 259 507 652 839 429 190 821 976 473 6 × 2 = 1 + 0.572 366 873 001 440 595 868 519 015 305 678 858 381 643 952 947 2;
  • 44) 0.572 366 873 001 440 595 868 519 015 305 678 858 381 643 952 947 2 × 2 = 1 + 0.144 733 746 002 881 191 737 038 030 611 357 716 763 287 905 894 4;
  • 45) 0.144 733 746 002 881 191 737 038 030 611 357 716 763 287 905 894 4 × 2 = 0 + 0.289 467 492 005 762 383 474 076 061 222 715 433 526 575 811 788 8;
  • 46) 0.289 467 492 005 762 383 474 076 061 222 715 433 526 575 811 788 8 × 2 = 0 + 0.578 934 984 011 524 766 948 152 122 445 430 867 053 151 623 577 6;
  • 47) 0.578 934 984 011 524 766 948 152 122 445 430 867 053 151 623 577 6 × 2 = 1 + 0.157 869 968 023 049 533 896 304 244 890 861 734 106 303 247 155 2;
  • 48) 0.157 869 968 023 049 533 896 304 244 890 861 734 106 303 247 155 2 × 2 = 0 + 0.315 739 936 046 099 067 792 608 489 781 723 468 212 606 494 310 4;
  • 49) 0.315 739 936 046 099 067 792 608 489 781 723 468 212 606 494 310 4 × 2 = 0 + 0.631 479 872 092 198 135 585 216 979 563 446 936 425 212 988 620 8;
  • 50) 0.631 479 872 092 198 135 585 216 979 563 446 936 425 212 988 620 8 × 2 = 1 + 0.262 959 744 184 396 271 170 433 959 126 893 872 850 425 977 241 6;
  • 51) 0.262 959 744 184 396 271 170 433 959 126 893 872 850 425 977 241 6 × 2 = 0 + 0.525 919 488 368 792 542 340 867 918 253 787 745 700 851 954 483 2;
  • 52) 0.525 919 488 368 792 542 340 867 918 253 787 745 700 851 954 483 2 × 2 = 1 + 0.051 838 976 737 585 084 681 735 836 507 575 491 401 703 908 966 4;
  • 53) 0.051 838 976 737 585 084 681 735 836 507 575 491 401 703 908 966 4 × 2 = 0 + 0.103 677 953 475 170 169 363 471 673 015 150 982 803 407 817 932 8;
  • 54) 0.103 677 953 475 170 169 363 471 673 015 150 982 803 407 817 932 8 × 2 = 0 + 0.207 355 906 950 340 338 726 943 346 030 301 965 606 815 635 865 6;
  • 55) 0.207 355 906 950 340 338 726 943 346 030 301 965 606 815 635 865 6 × 2 = 0 + 0.414 711 813 900 680 677 453 886 692 060 603 931 213 631 271 731 2;
  • 56) 0.414 711 813 900 680 677 453 886 692 060 603 931 213 631 271 731 2 × 2 = 0 + 0.829 423 627 801 361 354 907 773 384 121 207 862 427 262 543 462 4;
  • 57) 0.829 423 627 801 361 354 907 773 384 121 207 862 427 262 543 462 4 × 2 = 1 + 0.658 847 255 602 722 709 815 546 768 242 415 724 854 525 086 924 8;
  • 58) 0.658 847 255 602 722 709 815 546 768 242 415 724 854 525 086 924 8 × 2 = 1 + 0.317 694 511 205 445 419 631 093 536 484 831 449 709 050 173 849 6;
  • 59) 0.317 694 511 205 445 419 631 093 536 484 831 449 709 050 173 849 6 × 2 = 0 + 0.635 389 022 410 890 839 262 187 072 969 662 899 418 100 347 699 2;
  • 60) 0.635 389 022 410 890 839 262 187 072 969 662 899 418 100 347 699 2 × 2 = 1 + 0.270 778 044 821 781 678 524 374 145 939 325 798 836 200 695 398 4;
  • 61) 0.270 778 044 821 781 678 524 374 145 939 325 798 836 200 695 398 4 × 2 = 0 + 0.541 556 089 643 563 357 048 748 291 878 651 597 672 401 390 796 8;
  • 62) 0.541 556 089 643 563 357 048 748 291 878 651 597 672 401 390 796 8 × 2 = 1 + 0.083 112 179 287 126 714 097 496 583 757 303 195 344 802 781 593 6;
  • 63) 0.083 112 179 287 126 714 097 496 583 757 303 195 344 802 781 593 6 × 2 = 0 + 0.166 224 358 574 253 428 194 993 167 514 606 390 689 605 563 187 2;

We didn't get any fractional part that was equal to zero. But we had enough iterations (over Mantissa limit) and at least one integer that was different from zero => FULL STOP (Losing precision - the converted number we get in the end will be just a very good approximation of the initial one).


5. Construct the base 2 representation of the fractional part of the number.

Take all the integer parts of the multiplying operations, starting from the top of the constructed list above:


0.000 806 264 623 585 362 514 063 654 156 856 105 034 342 553 933 4(10) =


0.0000 0000 0011 0100 1101 0110 1110 0000 0011 0000 1011 0010 0101 0000 1101 010(2)

6. Positive number before normalization:

0.000 806 264 623 585 362 514 063 654 156 856 105 034 342 553 933 4(10) =


0.0000 0000 0011 0100 1101 0110 1110 0000 0011 0000 1011 0010 0101 0000 1101 010(2)

7. Normalize the binary representation of the number.

Shift the decimal mark 11 positions to the right, so that only one non zero digit remains to the left of it:


0.000 806 264 623 585 362 514 063 654 156 856 105 034 342 553 933 4(10) =


0.0000 0000 0011 0100 1101 0110 1110 0000 0011 0000 1011 0010 0101 0000 1101 010(2) =


0.0000 0000 0011 0100 1101 0110 1110 0000 0011 0000 1011 0010 0101 0000 1101 010(2) × 20 =


1.1010 0110 1011 0111 0000 0001 1000 0101 1001 0010 1000 0110 1010(2) × 2-11


8. Up to this moment, there are the following elements that would feed into the 64 bit double precision IEEE 754 binary floating point representation:

Sign 1 (a negative number)


Exponent (unadjusted): -11


Mantissa (not normalized):
1.1010 0110 1011 0111 0000 0001 1000 0101 1001 0010 1000 0110 1010


9. Adjust the exponent.

Use the 11 bit excess/bias notation:


Exponent (adjusted) =


Exponent (unadjusted) + 2(11-1) - 1 =


-11 + 2(11-1) - 1 =


(-11 + 1 023)(10) =


1 012(10)


10. Convert the adjusted exponent from the decimal (base 10) to 11 bit binary.

Use the same technique of repeatedly dividing by 2:


  • division = quotient + remainder;
  • 1 012 ÷ 2 = 506 + 0;
  • 506 ÷ 2 = 253 + 0;
  • 253 ÷ 2 = 126 + 1;
  • 126 ÷ 2 = 63 + 0;
  • 63 ÷ 2 = 31 + 1;
  • 31 ÷ 2 = 15 + 1;
  • 15 ÷ 2 = 7 + 1;
  • 7 ÷ 2 = 3 + 1;
  • 3 ÷ 2 = 1 + 1;
  • 1 ÷ 2 = 0 + 1;

11. Construct the base 2 representation of the adjusted exponent.

Take all the remainders starting from the bottom of the list constructed above.


Exponent (adjusted) =


1012(10) =


011 1111 0100(2)


12. Normalize the mantissa.

a) Remove the leading (the leftmost) bit, since it's allways 1, and the decimal point, if the case.


b) Adjust its length to 52 bits, only if necessary (not the case here).


Mantissa (normalized) =


1. 1010 0110 1011 0111 0000 0001 1000 0101 1001 0010 1000 0110 1010 =


1010 0110 1011 0111 0000 0001 1000 0101 1001 0010 1000 0110 1010


13. The three elements that make up the number's 64 bit double precision IEEE 754 binary floating point representation:

Sign (1 bit) =
1 (a negative number)


Exponent (11 bits) =
011 1111 0100


Mantissa (52 bits) =
1010 0110 1011 0111 0000 0001 1000 0101 1001 0010 1000 0110 1010


Decimal number -0.000 806 264 623 585 362 514 063 654 156 856 105 034 342 553 933 4 converted to 64 bit double precision IEEE 754 binary floating point representation:

1 - 011 1111 0100 - 1010 0110 1011 0111 0000 0001 1000 0101 1001 0010 1000 0110 1010


How to convert numbers from the decimal system (base ten) to 64 bit double precision IEEE 754 binary floating point standard

Follow the steps below to convert a base 10 decimal number to 64 bit double precision IEEE 754 binary floating point:

  • 1. If the number to be converted is negative, start with its the positive version.
  • 2. First convert the integer part. Divide repeatedly by 2 the positive representation of the integer number that is to be converted to binary, until we get a quotient that is equal to zero, keeping track of each remainder.
  • 3. Construct the base 2 representation of the positive integer part of the number, by taking all the remainders from the previous operations, starting from the bottom of the list constructed above. Thus, the last remainder of the divisions becomes the first symbol (the leftmost) of the base two number, while the first remainder becomes the last symbol (the rightmost).
  • 4. Then convert the fractional part. Multiply the number repeatedly by 2, until we get a fractional part that is equal to zero, keeping track of each integer part of the results.
  • 5. Construct the base 2 representation of the fractional part of the number, by taking all the integer parts of the multiplying operations, starting from the top of the list constructed above (they should appear in the binary representation, from left to right, in the order they have been calculated).
  • 6. Normalize the binary representation of the number, shifting the decimal mark (the decimal point) "n" positions either to the left, or to the right, so that only one non zero digit remains to the left of the decimal mark.
  • 7. Adjust the exponent in 11 bit excess/bias notation and then convert it from decimal (base 10) to 11 bit binary, by using the same technique of repeatedly dividing by 2, as shown above:
    Exponent (adjusted) = Exponent (unadjusted) + 2(11-1) - 1
  • 8. Normalize mantissa, remove the leading (leftmost) bit, since it's allways '1' (and the decimal mark, if the case) and adjust its length to 52 bits, either by removing the excess bits from the right (losing precision...) or by adding extra bits set on '0' to the right.
  • 9. Sign (it takes 1 bit) is either 1 for a negative or 0 for a positive number.

Example: convert the negative number -31.640 215 from the decimal system (base ten) to 64 bit double precision IEEE 754 binary floating point:

  • 1. Start with the positive version of the number:

    |-31.640 215| = 31.640 215

  • 2. First convert the integer part, 31. Divide it repeatedly by 2, keeping track of each remainder, until we get a quotient that is equal to zero:
    • division = quotient + remainder;
    • 31 ÷ 2 = 15 + 1;
    • 15 ÷ 2 = 7 + 1;
    • 7 ÷ 2 = 3 + 1;
    • 3 ÷ 2 = 1 + 1;
    • 1 ÷ 2 = 0 + 1;
    • We have encountered a quotient that is ZERO => FULL STOP
  • 3. Construct the base 2 representation of the integer part of the number by taking all the remainders of the previous dividing operations, starting from the bottom of the list constructed above:

    31(10) = 1 1111(2)

  • 4. Then, convert the fractional part, 0.640 215. Multiply repeatedly by 2, keeping track of each integer part of the results, until we get a fractional part that is equal to zero:
    • #) multiplying = integer + fractional part;
    • 1) 0.640 215 × 2 = 1 + 0.280 43;
    • 2) 0.280 43 × 2 = 0 + 0.560 86;
    • 3) 0.560 86 × 2 = 1 + 0.121 72;
    • 4) 0.121 72 × 2 = 0 + 0.243 44;
    • 5) 0.243 44 × 2 = 0 + 0.486 88;
    • 6) 0.486 88 × 2 = 0 + 0.973 76;
    • 7) 0.973 76 × 2 = 1 + 0.947 52;
    • 8) 0.947 52 × 2 = 1 + 0.895 04;
    • 9) 0.895 04 × 2 = 1 + 0.790 08;
    • 10) 0.790 08 × 2 = 1 + 0.580 16;
    • 11) 0.580 16 × 2 = 1 + 0.160 32;
    • 12) 0.160 32 × 2 = 0 + 0.320 64;
    • 13) 0.320 64 × 2 = 0 + 0.641 28;
    • 14) 0.641 28 × 2 = 1 + 0.282 56;
    • 15) 0.282 56 × 2 = 0 + 0.565 12;
    • 16) 0.565 12 × 2 = 1 + 0.130 24;
    • 17) 0.130 24 × 2 = 0 + 0.260 48;
    • 18) 0.260 48 × 2 = 0 + 0.520 96;
    • 19) 0.520 96 × 2 = 1 + 0.041 92;
    • 20) 0.041 92 × 2 = 0 + 0.083 84;
    • 21) 0.083 84 × 2 = 0 + 0.167 68;
    • 22) 0.167 68 × 2 = 0 + 0.335 36;
    • 23) 0.335 36 × 2 = 0 + 0.670 72;
    • 24) 0.670 72 × 2 = 1 + 0.341 44;
    • 25) 0.341 44 × 2 = 0 + 0.682 88;
    • 26) 0.682 88 × 2 = 1 + 0.365 76;
    • 27) 0.365 76 × 2 = 0 + 0.731 52;
    • 28) 0.731 52 × 2 = 1 + 0.463 04;
    • 29) 0.463 04 × 2 = 0 + 0.926 08;
    • 30) 0.926 08 × 2 = 1 + 0.852 16;
    • 31) 0.852 16 × 2 = 1 + 0.704 32;
    • 32) 0.704 32 × 2 = 1 + 0.408 64;
    • 33) 0.408 64 × 2 = 0 + 0.817 28;
    • 34) 0.817 28 × 2 = 1 + 0.634 56;
    • 35) 0.634 56 × 2 = 1 + 0.269 12;
    • 36) 0.269 12 × 2 = 0 + 0.538 24;
    • 37) 0.538 24 × 2 = 1 + 0.076 48;
    • 38) 0.076 48 × 2 = 0 + 0.152 96;
    • 39) 0.152 96 × 2 = 0 + 0.305 92;
    • 40) 0.305 92 × 2 = 0 + 0.611 84;
    • 41) 0.611 84 × 2 = 1 + 0.223 68;
    • 42) 0.223 68 × 2 = 0 + 0.447 36;
    • 43) 0.447 36 × 2 = 0 + 0.894 72;
    • 44) 0.894 72 × 2 = 1 + 0.789 44;
    • 45) 0.789 44 × 2 = 1 + 0.578 88;
    • 46) 0.578 88 × 2 = 1 + 0.157 76;
    • 47) 0.157 76 × 2 = 0 + 0.315 52;
    • 48) 0.315 52 × 2 = 0 + 0.631 04;
    • 49) 0.631 04 × 2 = 1 + 0.262 08;
    • 50) 0.262 08 × 2 = 0 + 0.524 16;
    • 51) 0.524 16 × 2 = 1 + 0.048 32;
    • 52) 0.048 32 × 2 = 0 + 0.096 64;
    • 53) 0.096 64 × 2 = 0 + 0.193 28;
    • We didn't get any fractional part that was equal to zero. But we had enough iterations (over Mantissa limit = 52) and at least one integer part that was different from zero => FULL STOP (losing precision...).
  • 5. Construct the base 2 representation of the fractional part of the number, by taking all the integer parts of the previous multiplying operations, starting from the top of the constructed list above:

    0.640 215(10) = 0.1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100 1010 0(2)

  • 6. Summarizing - the positive number before normalization:

    31.640 215(10) = 1 1111.1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100 1010 0(2)

  • 7. Normalize the binary representation of the number, shifting the decimal mark 4 positions to the left so that only one non-zero digit stays to the left of the decimal mark:

    31.640 215(10) =
    1 1111.1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100 1010 0(2) =
    1 1111.1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100 1010 0(2) × 20 =
    1.1111 1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100 1010 0(2) × 24

  • 8. Up to this moment, there are the following elements that would feed into the 64 bit double precision IEEE 754 binary floating point representation:

    Sign: 1 (a negative number)

    Exponent (unadjusted): 4

    Mantissa (not-normalized): 1.1111 1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100 1010 0

  • 9. Adjust the exponent in 11 bit excess/bias notation and then convert it from decimal (base 10) to 11 bit binary (base 2), by using the same technique of repeatedly dividing it by 2, as shown above:

    Exponent (adjusted) = Exponent (unadjusted) + 2(11-1) - 1 = (4 + 1023)(10) = 1027(10) =
    100 0000 0011(2)

  • 10. Normalize mantissa, remove the leading (leftmost) bit, since it's allways '1' (and the decimal sign) and adjust its length to 52 bits, by removing the excess bits, from the right (losing precision...):

    Mantissa (not-normalized): 1.1111 1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100 1010 0

    Mantissa (normalized): 1111 1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100

  • Conclusion:

    Sign (1 bit) = 1 (a negative number)

    Exponent (8 bits) = 100 0000 0011

    Mantissa (52 bits) = 1111 1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100

  • Number -31.640 215, converted from decimal system (base 10) to 64 bit double precision IEEE 754 binary floating point =
    1 - 100 0000 0011 - 1111 1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100