-2.211 829 052 383 358 300 119 548 661 699 653 280 265 920 329 838 990 854 Converted to 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard

Convert decimal -2.211 829 052 383 358 300 119 548 661 699 653 280 265 920 329 838 990 854(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
-2.211 829 052 383 358 300 119 548 661 699 653 280 265 920 329 838 990 854(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:

|-2.211 829 052 383 358 300 119 548 661 699 653 280 265 920 329 838 990 854| = 2.211 829 052 383 358 300 119 548 661 699 653 280 265 920 329 838 990 854


2. First, convert to binary (in base 2) the integer part: 2.
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;
  • 2 ÷ 2 = 1 + 0;
  • 1 ÷ 2 = 0 + 1;

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.

2(10) =


10(2)


4. Convert to binary (base 2) the fractional part: 0.211 829 052 383 358 300 119 548 661 699 653 280 265 920 329 838 990 854.

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) 0.211 829 052 383 358 300 119 548 661 699 653 280 265 920 329 838 990 854 × 2 = 0 + 0.423 658 104 766 716 600 239 097 323 399 306 560 531 840 659 677 981 708;
  • 2) 0.423 658 104 766 716 600 239 097 323 399 306 560 531 840 659 677 981 708 × 2 = 0 + 0.847 316 209 533 433 200 478 194 646 798 613 121 063 681 319 355 963 416;
  • 3) 0.847 316 209 533 433 200 478 194 646 798 613 121 063 681 319 355 963 416 × 2 = 1 + 0.694 632 419 066 866 400 956 389 293 597 226 242 127 362 638 711 926 832;
  • 4) 0.694 632 419 066 866 400 956 389 293 597 226 242 127 362 638 711 926 832 × 2 = 1 + 0.389 264 838 133 732 801 912 778 587 194 452 484 254 725 277 423 853 664;
  • 5) 0.389 264 838 133 732 801 912 778 587 194 452 484 254 725 277 423 853 664 × 2 = 0 + 0.778 529 676 267 465 603 825 557 174 388 904 968 509 450 554 847 707 328;
  • 6) 0.778 529 676 267 465 603 825 557 174 388 904 968 509 450 554 847 707 328 × 2 = 1 + 0.557 059 352 534 931 207 651 114 348 777 809 937 018 901 109 695 414 656;
  • 7) 0.557 059 352 534 931 207 651 114 348 777 809 937 018 901 109 695 414 656 × 2 = 1 + 0.114 118 705 069 862 415 302 228 697 555 619 874 037 802 219 390 829 312;
  • 8) 0.114 118 705 069 862 415 302 228 697 555 619 874 037 802 219 390 829 312 × 2 = 0 + 0.228 237 410 139 724 830 604 457 395 111 239 748 075 604 438 781 658 624;
  • 9) 0.228 237 410 139 724 830 604 457 395 111 239 748 075 604 438 781 658 624 × 2 = 0 + 0.456 474 820 279 449 661 208 914 790 222 479 496 151 208 877 563 317 248;
  • 10) 0.456 474 820 279 449 661 208 914 790 222 479 496 151 208 877 563 317 248 × 2 = 0 + 0.912 949 640 558 899 322 417 829 580 444 958 992 302 417 755 126 634 496;
  • 11) 0.912 949 640 558 899 322 417 829 580 444 958 992 302 417 755 126 634 496 × 2 = 1 + 0.825 899 281 117 798 644 835 659 160 889 917 984 604 835 510 253 268 992;
  • 12) 0.825 899 281 117 798 644 835 659 160 889 917 984 604 835 510 253 268 992 × 2 = 1 + 0.651 798 562 235 597 289 671 318 321 779 835 969 209 671 020 506 537 984;
  • 13) 0.651 798 562 235 597 289 671 318 321 779 835 969 209 671 020 506 537 984 × 2 = 1 + 0.303 597 124 471 194 579 342 636 643 559 671 938 419 342 041 013 075 968;
  • 14) 0.303 597 124 471 194 579 342 636 643 559 671 938 419 342 041 013 075 968 × 2 = 0 + 0.607 194 248 942 389 158 685 273 287 119 343 876 838 684 082 026 151 936;
  • 15) 0.607 194 248 942 389 158 685 273 287 119 343 876 838 684 082 026 151 936 × 2 = 1 + 0.214 388 497 884 778 317 370 546 574 238 687 753 677 368 164 052 303 872;
  • 16) 0.214 388 497 884 778 317 370 546 574 238 687 753 677 368 164 052 303 872 × 2 = 0 + 0.428 776 995 769 556 634 741 093 148 477 375 507 354 736 328 104 607 744;
  • 17) 0.428 776 995 769 556 634 741 093 148 477 375 507 354 736 328 104 607 744 × 2 = 0 + 0.857 553 991 539 113 269 482 186 296 954 751 014 709 472 656 209 215 488;
  • 18) 0.857 553 991 539 113 269 482 186 296 954 751 014 709 472 656 209 215 488 × 2 = 1 + 0.715 107 983 078 226 538 964 372 593 909 502 029 418 945 312 418 430 976;
  • 19) 0.715 107 983 078 226 538 964 372 593 909 502 029 418 945 312 418 430 976 × 2 = 1 + 0.430 215 966 156 453 077 928 745 187 819 004 058 837 890 624 836 861 952;
  • 20) 0.430 215 966 156 453 077 928 745 187 819 004 058 837 890 624 836 861 952 × 2 = 0 + 0.860 431 932 312 906 155 857 490 375 638 008 117 675 781 249 673 723 904;
  • 21) 0.860 431 932 312 906 155 857 490 375 638 008 117 675 781 249 673 723 904 × 2 = 1 + 0.720 863 864 625 812 311 714 980 751 276 016 235 351 562 499 347 447 808;
  • 22) 0.720 863 864 625 812 311 714 980 751 276 016 235 351 562 499 347 447 808 × 2 = 1 + 0.441 727 729 251 624 623 429 961 502 552 032 470 703 124 998 694 895 616;
  • 23) 0.441 727 729 251 624 623 429 961 502 552 032 470 703 124 998 694 895 616 × 2 = 0 + 0.883 455 458 503 249 246 859 923 005 104 064 941 406 249 997 389 791 232;
  • 24) 0.883 455 458 503 249 246 859 923 005 104 064 941 406 249 997 389 791 232 × 2 = 1 + 0.766 910 917 006 498 493 719 846 010 208 129 882 812 499 994 779 582 464;
  • 25) 0.766 910 917 006 498 493 719 846 010 208 129 882 812 499 994 779 582 464 × 2 = 1 + 0.533 821 834 012 996 987 439 692 020 416 259 765 624 999 989 559 164 928;
  • 26) 0.533 821 834 012 996 987 439 692 020 416 259 765 624 999 989 559 164 928 × 2 = 1 + 0.067 643 668 025 993 974 879 384 040 832 519 531 249 999 979 118 329 856;
  • 27) 0.067 643 668 025 993 974 879 384 040 832 519 531 249 999 979 118 329 856 × 2 = 0 + 0.135 287 336 051 987 949 758 768 081 665 039 062 499 999 958 236 659 712;
  • 28) 0.135 287 336 051 987 949 758 768 081 665 039 062 499 999 958 236 659 712 × 2 = 0 + 0.270 574 672 103 975 899 517 536 163 330 078 124 999 999 916 473 319 424;
  • 29) 0.270 574 672 103 975 899 517 536 163 330 078 124 999 999 916 473 319 424 × 2 = 0 + 0.541 149 344 207 951 799 035 072 326 660 156 249 999 999 832 946 638 848;
  • 30) 0.541 149 344 207 951 799 035 072 326 660 156 249 999 999 832 946 638 848 × 2 = 1 + 0.082 298 688 415 903 598 070 144 653 320 312 499 999 999 665 893 277 696;
  • 31) 0.082 298 688 415 903 598 070 144 653 320 312 499 999 999 665 893 277 696 × 2 = 0 + 0.164 597 376 831 807 196 140 289 306 640 624 999 999 999 331 786 555 392;
  • 32) 0.164 597 376 831 807 196 140 289 306 640 624 999 999 999 331 786 555 392 × 2 = 0 + 0.329 194 753 663 614 392 280 578 613 281 249 999 999 998 663 573 110 784;
  • 33) 0.329 194 753 663 614 392 280 578 613 281 249 999 999 998 663 573 110 784 × 2 = 0 + 0.658 389 507 327 228 784 561 157 226 562 499 999 999 997 327 146 221 568;
  • 34) 0.658 389 507 327 228 784 561 157 226 562 499 999 999 997 327 146 221 568 × 2 = 1 + 0.316 779 014 654 457 569 122 314 453 124 999 999 999 994 654 292 443 136;
  • 35) 0.316 779 014 654 457 569 122 314 453 124 999 999 999 994 654 292 443 136 × 2 = 0 + 0.633 558 029 308 915 138 244 628 906 249 999 999 999 989 308 584 886 272;
  • 36) 0.633 558 029 308 915 138 244 628 906 249 999 999 999 989 308 584 886 272 × 2 = 1 + 0.267 116 058 617 830 276 489 257 812 499 999 999 999 978 617 169 772 544;
  • 37) 0.267 116 058 617 830 276 489 257 812 499 999 999 999 978 617 169 772 544 × 2 = 0 + 0.534 232 117 235 660 552 978 515 624 999 999 999 999 957 234 339 545 088;
  • 38) 0.534 232 117 235 660 552 978 515 624 999 999 999 999 957 234 339 545 088 × 2 = 1 + 0.068 464 234 471 321 105 957 031 249 999 999 999 999 914 468 679 090 176;
  • 39) 0.068 464 234 471 321 105 957 031 249 999 999 999 999 914 468 679 090 176 × 2 = 0 + 0.136 928 468 942 642 211 914 062 499 999 999 999 999 828 937 358 180 352;
  • 40) 0.136 928 468 942 642 211 914 062 499 999 999 999 999 828 937 358 180 352 × 2 = 0 + 0.273 856 937 885 284 423 828 124 999 999 999 999 999 657 874 716 360 704;
  • 41) 0.273 856 937 885 284 423 828 124 999 999 999 999 999 657 874 716 360 704 × 2 = 0 + 0.547 713 875 770 568 847 656 249 999 999 999 999 999 315 749 432 721 408;
  • 42) 0.547 713 875 770 568 847 656 249 999 999 999 999 999 315 749 432 721 408 × 2 = 1 + 0.095 427 751 541 137 695 312 499 999 999 999 999 998 631 498 865 442 816;
  • 43) 0.095 427 751 541 137 695 312 499 999 999 999 999 998 631 498 865 442 816 × 2 = 0 + 0.190 855 503 082 275 390 624 999 999 999 999 999 997 262 997 730 885 632;
  • 44) 0.190 855 503 082 275 390 624 999 999 999 999 999 997 262 997 730 885 632 × 2 = 0 + 0.381 711 006 164 550 781 249 999 999 999 999 999 994 525 995 461 771 264;
  • 45) 0.381 711 006 164 550 781 249 999 999 999 999 999 994 525 995 461 771 264 × 2 = 0 + 0.763 422 012 329 101 562 499 999 999 999 999 999 989 051 990 923 542 528;
  • 46) 0.763 422 012 329 101 562 499 999 999 999 999 999 989 051 990 923 542 528 × 2 = 1 + 0.526 844 024 658 203 124 999 999 999 999 999 999 978 103 981 847 085 056;
  • 47) 0.526 844 024 658 203 124 999 999 999 999 999 999 978 103 981 847 085 056 × 2 = 1 + 0.053 688 049 316 406 249 999 999 999 999 999 999 956 207 963 694 170 112;
  • 48) 0.053 688 049 316 406 249 999 999 999 999 999 999 956 207 963 694 170 112 × 2 = 0 + 0.107 376 098 632 812 499 999 999 999 999 999 999 912 415 927 388 340 224;
  • 49) 0.107 376 098 632 812 499 999 999 999 999 999 999 912 415 927 388 340 224 × 2 = 0 + 0.214 752 197 265 624 999 999 999 999 999 999 999 824 831 854 776 680 448;
  • 50) 0.214 752 197 265 624 999 999 999 999 999 999 999 824 831 854 776 680 448 × 2 = 0 + 0.429 504 394 531 249 999 999 999 999 999 999 999 649 663 709 553 360 896;
  • 51) 0.429 504 394 531 249 999 999 999 999 999 999 999 649 663 709 553 360 896 × 2 = 0 + 0.859 008 789 062 499 999 999 999 999 999 999 999 299 327 419 106 721 792;
  • 52) 0.859 008 789 062 499 999 999 999 999 999 999 999 299 327 419 106 721 792 × 2 = 1 + 0.718 017 578 124 999 999 999 999 999 999 999 998 598 654 838 213 443 584;
  • 53) 0.718 017 578 124 999 999 999 999 999 999 999 998 598 654 838 213 443 584 × 2 = 1 + 0.436 035 156 249 999 999 999 999 999 999 999 997 197 309 676 426 887 168;

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:


0.211 829 052 383 358 300 119 548 661 699 653 280 265 920 329 838 990 854(10) =


0.0011 0110 0011 1010 0110 1101 1100 0100 0101 0100 0100 0110 0001 1(2)

6. Positive number before normalization:

2.211 829 052 383 358 300 119 548 661 699 653 280 265 920 329 838 990 854(10) =


10.0011 0110 0011 1010 0110 1101 1100 0100 0101 0100 0100 0110 0001 1(2)

7. Normalize the binary representation of the number.

Shift the decimal mark 1 positions to the left, so that only one non zero digit remains to the left of it:


2.211 829 052 383 358 300 119 548 661 699 653 280 265 920 329 838 990 854(10) =


10.0011 0110 0011 1010 0110 1101 1100 0100 0101 0100 0100 0110 0001 1(2) =


10.0011 0110 0011 1010 0110 1101 1100 0100 0101 0100 0100 0110 0001 1(2) × 20 =


1.0001 1011 0001 1101 0011 0110 1110 0010 0010 1010 0010 0011 0000 11(2) × 21


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): 1


Mantissa (not normalized):
1.0001 1011 0001 1101 0011 0110 1110 0010 0010 1010 0010 0011 0000 11


9. Adjust the exponent.

Use the 11 bit excess/bias notation:


Exponent (adjusted) =


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


1 + 2(11-1) - 1 =


(1 + 1 023)(10) =


1 024(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;
  • 1 024 ÷ 2 = 512 + 0;
  • 512 ÷ 2 = 256 + 0;
  • 256 ÷ 2 = 128 + 0;
  • 128 ÷ 2 = 64 + 0;
  • 64 ÷ 2 = 32 + 0;
  • 32 ÷ 2 = 16 + 0;
  • 16 ÷ 2 = 8 + 0;
  • 8 ÷ 2 = 4 + 0;
  • 4 ÷ 2 = 2 + 0;
  • 2 ÷ 2 = 1 + 0;
  • 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) =


1024(10) =


100 0000 0000(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, by removing the excess bits, from the right (if any of the excess bits is set on 1, we are losing precision...).


Mantissa (normalized) =


1. 0001 1011 0001 1101 0011 0110 1110 0010 0010 1010 0010 0011 0000 11 =


0001 1011 0001 1101 0011 0110 1110 0010 0010 1010 0010 0011 0000


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) =
100 0000 0000


Mantissa (52 bits) =
0001 1011 0001 1101 0011 0110 1110 0010 0010 1010 0010 0011 0000


Decimal number -2.211 829 052 383 358 300 119 548 661 699 653 280 265 920 329 838 990 854 converted to 64 bit double precision IEEE 754 binary floating point representation:

1 - 100 0000 0000 - 0001 1011 0001 1101 0011 0110 1110 0010 0010 1010 0010 0011 0000


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