-0.000 806 264 623 585 362 514 063 654 156 856 105 034 330 8 Converted to 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard

Convert decimal -0.000 806 264 623 585 362 514 063 654 156 856 105 034 330 8(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
-0.000 806 264 623 585 362 514 063 654 156 856 105 034 330 8(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:

|-0.000 806 264 623 585 362 514 063 654 156 856 105 034 330 8| = 0.000 806 264 623 585 362 514 063 654 156 856 105 034 330 8


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: 0.000 806 264 623 585 362 514 063 654 156 856 105 034 330 8.

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) 0.000 806 264 623 585 362 514 063 654 156 856 105 034 330 8 × 2 = 0 + 0.001 612 529 247 170 725 028 127 308 313 712 210 068 661 6;
  • 2) 0.001 612 529 247 170 725 028 127 308 313 712 210 068 661 6 × 2 = 0 + 0.003 225 058 494 341 450 056 254 616 627 424 420 137 323 2;
  • 3) 0.003 225 058 494 341 450 056 254 616 627 424 420 137 323 2 × 2 = 0 + 0.006 450 116 988 682 900 112 509 233 254 848 840 274 646 4;
  • 4) 0.006 450 116 988 682 900 112 509 233 254 848 840 274 646 4 × 2 = 0 + 0.012 900 233 977 365 800 225 018 466 509 697 680 549 292 8;
  • 5) 0.012 900 233 977 365 800 225 018 466 509 697 680 549 292 8 × 2 = 0 + 0.025 800 467 954 731 600 450 036 933 019 395 361 098 585 6;
  • 6) 0.025 800 467 954 731 600 450 036 933 019 395 361 098 585 6 × 2 = 0 + 0.051 600 935 909 463 200 900 073 866 038 790 722 197 171 2;
  • 7) 0.051 600 935 909 463 200 900 073 866 038 790 722 197 171 2 × 2 = 0 + 0.103 201 871 818 926 401 800 147 732 077 581 444 394 342 4;
  • 8) 0.103 201 871 818 926 401 800 147 732 077 581 444 394 342 4 × 2 = 0 + 0.206 403 743 637 852 803 600 295 464 155 162 888 788 684 8;
  • 9) 0.206 403 743 637 852 803 600 295 464 155 162 888 788 684 8 × 2 = 0 + 0.412 807 487 275 705 607 200 590 928 310 325 777 577 369 6;
  • 10) 0.412 807 487 275 705 607 200 590 928 310 325 777 577 369 6 × 2 = 0 + 0.825 614 974 551 411 214 401 181 856 620 651 555 154 739 2;
  • 11) 0.825 614 974 551 411 214 401 181 856 620 651 555 154 739 2 × 2 = 1 + 0.651 229 949 102 822 428 802 363 713 241 303 110 309 478 4;
  • 12) 0.651 229 949 102 822 428 802 363 713 241 303 110 309 478 4 × 2 = 1 + 0.302 459 898 205 644 857 604 727 426 482 606 220 618 956 8;
  • 13) 0.302 459 898 205 644 857 604 727 426 482 606 220 618 956 8 × 2 = 0 + 0.604 919 796 411 289 715 209 454 852 965 212 441 237 913 6;
  • 14) 0.604 919 796 411 289 715 209 454 852 965 212 441 237 913 6 × 2 = 1 + 0.209 839 592 822 579 430 418 909 705 930 424 882 475 827 2;
  • 15) 0.209 839 592 822 579 430 418 909 705 930 424 882 475 827 2 × 2 = 0 + 0.419 679 185 645 158 860 837 819 411 860 849 764 951 654 4;
  • 16) 0.419 679 185 645 158 860 837 819 411 860 849 764 951 654 4 × 2 = 0 + 0.839 358 371 290 317 721 675 638 823 721 699 529 903 308 8;
  • 17) 0.839 358 371 290 317 721 675 638 823 721 699 529 903 308 8 × 2 = 1 + 0.678 716 742 580 635 443 351 277 647 443 399 059 806 617 6;
  • 18) 0.678 716 742 580 635 443 351 277 647 443 399 059 806 617 6 × 2 = 1 + 0.357 433 485 161 270 886 702 555 294 886 798 119 613 235 2;
  • 19) 0.357 433 485 161 270 886 702 555 294 886 798 119 613 235 2 × 2 = 0 + 0.714 866 970 322 541 773 405 110 589 773 596 239 226 470 4;
  • 20) 0.714 866 970 322 541 773 405 110 589 773 596 239 226 470 4 × 2 = 1 + 0.429 733 940 645 083 546 810 221 179 547 192 478 452 940 8;
  • 21) 0.429 733 940 645 083 546 810 221 179 547 192 478 452 940 8 × 2 = 0 + 0.859 467 881 290 167 093 620 442 359 094 384 956 905 881 6;
  • 22) 0.859 467 881 290 167 093 620 442 359 094 384 956 905 881 6 × 2 = 1 + 0.718 935 762 580 334 187 240 884 718 188 769 913 811 763 2;
  • 23) 0.718 935 762 580 334 187 240 884 718 188 769 913 811 763 2 × 2 = 1 + 0.437 871 525 160 668 374 481 769 436 377 539 827 623 526 4;
  • 24) 0.437 871 525 160 668 374 481 769 436 377 539 827 623 526 4 × 2 = 0 + 0.875 743 050 321 336 748 963 538 872 755 079 655 247 052 8;
  • 25) 0.875 743 050 321 336 748 963 538 872 755 079 655 247 052 8 × 2 = 1 + 0.751 486 100 642 673 497 927 077 745 510 159 310 494 105 6;
  • 26) 0.751 486 100 642 673 497 927 077 745 510 159 310 494 105 6 × 2 = 1 + 0.502 972 201 285 346 995 854 155 491 020 318 620 988 211 2;
  • 27) 0.502 972 201 285 346 995 854 155 491 020 318 620 988 211 2 × 2 = 1 + 0.005 944 402 570 693 991 708 310 982 040 637 241 976 422 4;
  • 28) 0.005 944 402 570 693 991 708 310 982 040 637 241 976 422 4 × 2 = 0 + 0.011 888 805 141 387 983 416 621 964 081 274 483 952 844 8;
  • 29) 0.011 888 805 141 387 983 416 621 964 081 274 483 952 844 8 × 2 = 0 + 0.023 777 610 282 775 966 833 243 928 162 548 967 905 689 6;
  • 30) 0.023 777 610 282 775 966 833 243 928 162 548 967 905 689 6 × 2 = 0 + 0.047 555 220 565 551 933 666 487 856 325 097 935 811 379 2;
  • 31) 0.047 555 220 565 551 933 666 487 856 325 097 935 811 379 2 × 2 = 0 + 0.095 110 441 131 103 867 332 975 712 650 195 871 622 758 4;
  • 32) 0.095 110 441 131 103 867 332 975 712 650 195 871 622 758 4 × 2 = 0 + 0.190 220 882 262 207 734 665 951 425 300 391 743 245 516 8;
  • 33) 0.190 220 882 262 207 734 665 951 425 300 391 743 245 516 8 × 2 = 0 + 0.380 441 764 524 415 469 331 902 850 600 783 486 491 033 6;
  • 34) 0.380 441 764 524 415 469 331 902 850 600 783 486 491 033 6 × 2 = 0 + 0.760 883 529 048 830 938 663 805 701 201 566 972 982 067 2;
  • 35) 0.760 883 529 048 830 938 663 805 701 201 566 972 982 067 2 × 2 = 1 + 0.521 767 058 097 661 877 327 611 402 403 133 945 964 134 4;
  • 36) 0.521 767 058 097 661 877 327 611 402 403 133 945 964 134 4 × 2 = 1 + 0.043 534 116 195 323 754 655 222 804 806 267 891 928 268 8;
  • 37) 0.043 534 116 195 323 754 655 222 804 806 267 891 928 268 8 × 2 = 0 + 0.087 068 232 390 647 509 310 445 609 612 535 783 856 537 6;
  • 38) 0.087 068 232 390 647 509 310 445 609 612 535 783 856 537 6 × 2 = 0 + 0.174 136 464 781 295 018 620 891 219 225 071 567 713 075 2;
  • 39) 0.174 136 464 781 295 018 620 891 219 225 071 567 713 075 2 × 2 = 0 + 0.348 272 929 562 590 037 241 782 438 450 143 135 426 150 4;
  • 40) 0.348 272 929 562 590 037 241 782 438 450 143 135 426 150 4 × 2 = 0 + 0.696 545 859 125 180 074 483 564 876 900 286 270 852 300 8;
  • 41) 0.696 545 859 125 180 074 483 564 876 900 286 270 852 300 8 × 2 = 1 + 0.393 091 718 250 360 148 967 129 753 800 572 541 704 601 6;
  • 42) 0.393 091 718 250 360 148 967 129 753 800 572 541 704 601 6 × 2 = 0 + 0.786 183 436 500 720 297 934 259 507 601 145 083 409 203 2;
  • 43) 0.786 183 436 500 720 297 934 259 507 601 145 083 409 203 2 × 2 = 1 + 0.572 366 873 001 440 595 868 519 015 202 290 166 818 406 4;
  • 44) 0.572 366 873 001 440 595 868 519 015 202 290 166 818 406 4 × 2 = 1 + 0.144 733 746 002 881 191 737 038 030 404 580 333 636 812 8;
  • 45) 0.144 733 746 002 881 191 737 038 030 404 580 333 636 812 8 × 2 = 0 + 0.289 467 492 005 762 383 474 076 060 809 160 667 273 625 6;
  • 46) 0.289 467 492 005 762 383 474 076 060 809 160 667 273 625 6 × 2 = 0 + 0.578 934 984 011 524 766 948 152 121 618 321 334 547 251 2;
  • 47) 0.578 934 984 011 524 766 948 152 121 618 321 334 547 251 2 × 2 = 1 + 0.157 869 968 023 049 533 896 304 243 236 642 669 094 502 4;
  • 48) 0.157 869 968 023 049 533 896 304 243 236 642 669 094 502 4 × 2 = 0 + 0.315 739 936 046 099 067 792 608 486 473 285 338 189 004 8;
  • 49) 0.315 739 936 046 099 067 792 608 486 473 285 338 189 004 8 × 2 = 0 + 0.631 479 872 092 198 135 585 216 972 946 570 676 378 009 6;
  • 50) 0.631 479 872 092 198 135 585 216 972 946 570 676 378 009 6 × 2 = 1 + 0.262 959 744 184 396 271 170 433 945 893 141 352 756 019 2;
  • 51) 0.262 959 744 184 396 271 170 433 945 893 141 352 756 019 2 × 2 = 0 + 0.525 919 488 368 792 542 340 867 891 786 282 705 512 038 4;
  • 52) 0.525 919 488 368 792 542 340 867 891 786 282 705 512 038 4 × 2 = 1 + 0.051 838 976 737 585 084 681 735 783 572 565 411 024 076 8;
  • 53) 0.051 838 976 737 585 084 681 735 783 572 565 411 024 076 8 × 2 = 0 + 0.103 677 953 475 170 169 363 471 567 145 130 822 048 153 6;
  • 54) 0.103 677 953 475 170 169 363 471 567 145 130 822 048 153 6 × 2 = 0 + 0.207 355 906 950 340 338 726 943 134 290 261 644 096 307 2;
  • 55) 0.207 355 906 950 340 338 726 943 134 290 261 644 096 307 2 × 2 = 0 + 0.414 711 813 900 680 677 453 886 268 580 523 288 192 614 4;
  • 56) 0.414 711 813 900 680 677 453 886 268 580 523 288 192 614 4 × 2 = 0 + 0.829 423 627 801 361 354 907 772 537 161 046 576 385 228 8;
  • 57) 0.829 423 627 801 361 354 907 772 537 161 046 576 385 228 8 × 2 = 1 + 0.658 847 255 602 722 709 815 545 074 322 093 152 770 457 6;
  • 58) 0.658 847 255 602 722 709 815 545 074 322 093 152 770 457 6 × 2 = 1 + 0.317 694 511 205 445 419 631 090 148 644 186 305 540 915 2;
  • 59) 0.317 694 511 205 445 419 631 090 148 644 186 305 540 915 2 × 2 = 0 + 0.635 389 022 410 890 839 262 180 297 288 372 611 081 830 4;
  • 60) 0.635 389 022 410 890 839 262 180 297 288 372 611 081 830 4 × 2 = 1 + 0.270 778 044 821 781 678 524 360 594 576 745 222 163 660 8;
  • 61) 0.270 778 044 821 781 678 524 360 594 576 745 222 163 660 8 × 2 = 0 + 0.541 556 089 643 563 357 048 721 189 153 490 444 327 321 6;
  • 62) 0.541 556 089 643 563 357 048 721 189 153 490 444 327 321 6 × 2 = 1 + 0.083 112 179 287 126 714 097 442 378 306 980 888 654 643 2;
  • 63) 0.083 112 179 287 126 714 097 442 378 306 980 888 654 643 2 × 2 = 0 + 0.166 224 358 574 253 428 194 884 756 613 961 777 309 286 4;

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:


0.000 806 264 623 585 362 514 063 654 156 856 105 034 330 8(10) =


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

6. Positive number before normalization:

0.000 806 264 623 585 362 514 063 654 156 856 105 034 330 8(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:


0.000 806 264 623 585 362 514 063 654 156 856 105 034 330 8(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 -0.000 806 264 623 585 362 514 063 654 156 856 105 034 330 8 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