0.000 020 830 729 321 671 205 134 999 154 509 660 631 7 Converted to 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard

Convert decimal 0.000 020 830 729 321 671 205 134 999 154 509 660 631 7(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
0.000 020 830 729 321 671 205 134 999 154 509 660 631 7(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. 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;

2. 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)


3. Convert to binary (base 2) the fractional part: 0.000 020 830 729 321 671 205 134 999 154 509 660 631 7.

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) 0.000 020 830 729 321 671 205 134 999 154 509 660 631 7 × 2 = 0 + 0.000 041 661 458 643 342 410 269 998 309 019 321 263 4;
  • 2) 0.000 041 661 458 643 342 410 269 998 309 019 321 263 4 × 2 = 0 + 0.000 083 322 917 286 684 820 539 996 618 038 642 526 8;
  • 3) 0.000 083 322 917 286 684 820 539 996 618 038 642 526 8 × 2 = 0 + 0.000 166 645 834 573 369 641 079 993 236 077 285 053 6;
  • 4) 0.000 166 645 834 573 369 641 079 993 236 077 285 053 6 × 2 = 0 + 0.000 333 291 669 146 739 282 159 986 472 154 570 107 2;
  • 5) 0.000 333 291 669 146 739 282 159 986 472 154 570 107 2 × 2 = 0 + 0.000 666 583 338 293 478 564 319 972 944 309 140 214 4;
  • 6) 0.000 666 583 338 293 478 564 319 972 944 309 140 214 4 × 2 = 0 + 0.001 333 166 676 586 957 128 639 945 888 618 280 428 8;
  • 7) 0.001 333 166 676 586 957 128 639 945 888 618 280 428 8 × 2 = 0 + 0.002 666 333 353 173 914 257 279 891 777 236 560 857 6;
  • 8) 0.002 666 333 353 173 914 257 279 891 777 236 560 857 6 × 2 = 0 + 0.005 332 666 706 347 828 514 559 783 554 473 121 715 2;
  • 9) 0.005 332 666 706 347 828 514 559 783 554 473 121 715 2 × 2 = 0 + 0.010 665 333 412 695 657 029 119 567 108 946 243 430 4;
  • 10) 0.010 665 333 412 695 657 029 119 567 108 946 243 430 4 × 2 = 0 + 0.021 330 666 825 391 314 058 239 134 217 892 486 860 8;
  • 11) 0.021 330 666 825 391 314 058 239 134 217 892 486 860 8 × 2 = 0 + 0.042 661 333 650 782 628 116 478 268 435 784 973 721 6;
  • 12) 0.042 661 333 650 782 628 116 478 268 435 784 973 721 6 × 2 = 0 + 0.085 322 667 301 565 256 232 956 536 871 569 947 443 2;
  • 13) 0.085 322 667 301 565 256 232 956 536 871 569 947 443 2 × 2 = 0 + 0.170 645 334 603 130 512 465 913 073 743 139 894 886 4;
  • 14) 0.170 645 334 603 130 512 465 913 073 743 139 894 886 4 × 2 = 0 + 0.341 290 669 206 261 024 931 826 147 486 279 789 772 8;
  • 15) 0.341 290 669 206 261 024 931 826 147 486 279 789 772 8 × 2 = 0 + 0.682 581 338 412 522 049 863 652 294 972 559 579 545 6;
  • 16) 0.682 581 338 412 522 049 863 652 294 972 559 579 545 6 × 2 = 1 + 0.365 162 676 825 044 099 727 304 589 945 119 159 091 2;
  • 17) 0.365 162 676 825 044 099 727 304 589 945 119 159 091 2 × 2 = 0 + 0.730 325 353 650 088 199 454 609 179 890 238 318 182 4;
  • 18) 0.730 325 353 650 088 199 454 609 179 890 238 318 182 4 × 2 = 1 + 0.460 650 707 300 176 398 909 218 359 780 476 636 364 8;
  • 19) 0.460 650 707 300 176 398 909 218 359 780 476 636 364 8 × 2 = 0 + 0.921 301 414 600 352 797 818 436 719 560 953 272 729 6;
  • 20) 0.921 301 414 600 352 797 818 436 719 560 953 272 729 6 × 2 = 1 + 0.842 602 829 200 705 595 636 873 439 121 906 545 459 2;
  • 21) 0.842 602 829 200 705 595 636 873 439 121 906 545 459 2 × 2 = 1 + 0.685 205 658 401 411 191 273 746 878 243 813 090 918 4;
  • 22) 0.685 205 658 401 411 191 273 746 878 243 813 090 918 4 × 2 = 1 + 0.370 411 316 802 822 382 547 493 756 487 626 181 836 8;
  • 23) 0.370 411 316 802 822 382 547 493 756 487 626 181 836 8 × 2 = 0 + 0.740 822 633 605 644 765 094 987 512 975 252 363 673 6;
  • 24) 0.740 822 633 605 644 765 094 987 512 975 252 363 673 6 × 2 = 1 + 0.481 645 267 211 289 530 189 975 025 950 504 727 347 2;
  • 25) 0.481 645 267 211 289 530 189 975 025 950 504 727 347 2 × 2 = 0 + 0.963 290 534 422 579 060 379 950 051 901 009 454 694 4;
  • 26) 0.963 290 534 422 579 060 379 950 051 901 009 454 694 4 × 2 = 1 + 0.926 581 068 845 158 120 759 900 103 802 018 909 388 8;
  • 27) 0.926 581 068 845 158 120 759 900 103 802 018 909 388 8 × 2 = 1 + 0.853 162 137 690 316 241 519 800 207 604 037 818 777 6;
  • 28) 0.853 162 137 690 316 241 519 800 207 604 037 818 777 6 × 2 = 1 + 0.706 324 275 380 632 483 039 600 415 208 075 637 555 2;
  • 29) 0.706 324 275 380 632 483 039 600 415 208 075 637 555 2 × 2 = 1 + 0.412 648 550 761 264 966 079 200 830 416 151 275 110 4;
  • 30) 0.412 648 550 761 264 966 079 200 830 416 151 275 110 4 × 2 = 0 + 0.825 297 101 522 529 932 158 401 660 832 302 550 220 8;
  • 31) 0.825 297 101 522 529 932 158 401 660 832 302 550 220 8 × 2 = 1 + 0.650 594 203 045 059 864 316 803 321 664 605 100 441 6;
  • 32) 0.650 594 203 045 059 864 316 803 321 664 605 100 441 6 × 2 = 1 + 0.301 188 406 090 119 728 633 606 643 329 210 200 883 2;
  • 33) 0.301 188 406 090 119 728 633 606 643 329 210 200 883 2 × 2 = 0 + 0.602 376 812 180 239 457 267 213 286 658 420 401 766 4;
  • 34) 0.602 376 812 180 239 457 267 213 286 658 420 401 766 4 × 2 = 1 + 0.204 753 624 360 478 914 534 426 573 316 840 803 532 8;
  • 35) 0.204 753 624 360 478 914 534 426 573 316 840 803 532 8 × 2 = 0 + 0.409 507 248 720 957 829 068 853 146 633 681 607 065 6;
  • 36) 0.409 507 248 720 957 829 068 853 146 633 681 607 065 6 × 2 = 0 + 0.819 014 497 441 915 658 137 706 293 267 363 214 131 2;
  • 37) 0.819 014 497 441 915 658 137 706 293 267 363 214 131 2 × 2 = 1 + 0.638 028 994 883 831 316 275 412 586 534 726 428 262 4;
  • 38) 0.638 028 994 883 831 316 275 412 586 534 726 428 262 4 × 2 = 1 + 0.276 057 989 767 662 632 550 825 173 069 452 856 524 8;
  • 39) 0.276 057 989 767 662 632 550 825 173 069 452 856 524 8 × 2 = 0 + 0.552 115 979 535 325 265 101 650 346 138 905 713 049 6;
  • 40) 0.552 115 979 535 325 265 101 650 346 138 905 713 049 6 × 2 = 1 + 0.104 231 959 070 650 530 203 300 692 277 811 426 099 2;
  • 41) 0.104 231 959 070 650 530 203 300 692 277 811 426 099 2 × 2 = 0 + 0.208 463 918 141 301 060 406 601 384 555 622 852 198 4;
  • 42) 0.208 463 918 141 301 060 406 601 384 555 622 852 198 4 × 2 = 0 + 0.416 927 836 282 602 120 813 202 769 111 245 704 396 8;
  • 43) 0.416 927 836 282 602 120 813 202 769 111 245 704 396 8 × 2 = 0 + 0.833 855 672 565 204 241 626 405 538 222 491 408 793 6;
  • 44) 0.833 855 672 565 204 241 626 405 538 222 491 408 793 6 × 2 = 1 + 0.667 711 345 130 408 483 252 811 076 444 982 817 587 2;
  • 45) 0.667 711 345 130 408 483 252 811 076 444 982 817 587 2 × 2 = 1 + 0.335 422 690 260 816 966 505 622 152 889 965 635 174 4;
  • 46) 0.335 422 690 260 816 966 505 622 152 889 965 635 174 4 × 2 = 0 + 0.670 845 380 521 633 933 011 244 305 779 931 270 348 8;
  • 47) 0.670 845 380 521 633 933 011 244 305 779 931 270 348 8 × 2 = 1 + 0.341 690 761 043 267 866 022 488 611 559 862 540 697 6;
  • 48) 0.341 690 761 043 267 866 022 488 611 559 862 540 697 6 × 2 = 0 + 0.683 381 522 086 535 732 044 977 223 119 725 081 395 2;
  • 49) 0.683 381 522 086 535 732 044 977 223 119 725 081 395 2 × 2 = 1 + 0.366 763 044 173 071 464 089 954 446 239 450 162 790 4;
  • 50) 0.366 763 044 173 071 464 089 954 446 239 450 162 790 4 × 2 = 0 + 0.733 526 088 346 142 928 179 908 892 478 900 325 580 8;
  • 51) 0.733 526 088 346 142 928 179 908 892 478 900 325 580 8 × 2 = 1 + 0.467 052 176 692 285 856 359 817 784 957 800 651 161 6;
  • 52) 0.467 052 176 692 285 856 359 817 784 957 800 651 161 6 × 2 = 0 + 0.934 104 353 384 571 712 719 635 569 915 601 302 323 2;
  • 53) 0.934 104 353 384 571 712 719 635 569 915 601 302 323 2 × 2 = 1 + 0.868 208 706 769 143 425 439 271 139 831 202 604 646 4;
  • 54) 0.868 208 706 769 143 425 439 271 139 831 202 604 646 4 × 2 = 1 + 0.736 417 413 538 286 850 878 542 279 662 405 209 292 8;
  • 55) 0.736 417 413 538 286 850 878 542 279 662 405 209 292 8 × 2 = 1 + 0.472 834 827 076 573 701 757 084 559 324 810 418 585 6;
  • 56) 0.472 834 827 076 573 701 757 084 559 324 810 418 585 6 × 2 = 0 + 0.945 669 654 153 147 403 514 169 118 649 620 837 171 2;
  • 57) 0.945 669 654 153 147 403 514 169 118 649 620 837 171 2 × 2 = 1 + 0.891 339 308 306 294 807 028 338 237 299 241 674 342 4;
  • 58) 0.891 339 308 306 294 807 028 338 237 299 241 674 342 4 × 2 = 1 + 0.782 678 616 612 589 614 056 676 474 598 483 348 684 8;
  • 59) 0.782 678 616 612 589 614 056 676 474 598 483 348 684 8 × 2 = 1 + 0.565 357 233 225 179 228 113 352 949 196 966 697 369 6;
  • 60) 0.565 357 233 225 179 228 113 352 949 196 966 697 369 6 × 2 = 1 + 0.130 714 466 450 358 456 226 705 898 393 933 394 739 2;
  • 61) 0.130 714 466 450 358 456 226 705 898 393 933 394 739 2 × 2 = 0 + 0.261 428 932 900 716 912 453 411 796 787 866 789 478 4;
  • 62) 0.261 428 932 900 716 912 453 411 796 787 866 789 478 4 × 2 = 0 + 0.522 857 865 801 433 824 906 823 593 575 733 578 956 8;
  • 63) 0.522 857 865 801 433 824 906 823 593 575 733 578 956 8 × 2 = 1 + 0.045 715 731 602 867 649 813 647 187 151 467 157 913 6;
  • 64) 0.045 715 731 602 867 649 813 647 187 151 467 157 913 6 × 2 = 0 + 0.091 431 463 205 735 299 627 294 374 302 934 315 827 2;
  • 65) 0.091 431 463 205 735 299 627 294 374 302 934 315 827 2 × 2 = 0 + 0.182 862 926 411 470 599 254 588 748 605 868 631 654 4;
  • 66) 0.182 862 926 411 470 599 254 588 748 605 868 631 654 4 × 2 = 0 + 0.365 725 852 822 941 198 509 177 497 211 737 263 308 8;
  • 67) 0.365 725 852 822 941 198 509 177 497 211 737 263 308 8 × 2 = 0 + 0.731 451 705 645 882 397 018 354 994 423 474 526 617 6;
  • 68) 0.731 451 705 645 882 397 018 354 994 423 474 526 617 6 × 2 = 1 + 0.462 903 411 291 764 794 036 709 988 846 949 053 235 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).


4. 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:


0.000 020 830 729 321 671 205 134 999 154 509 660 631 7(10) =


0.0000 0000 0000 0001 0101 1101 0111 1011 0100 1101 0001 1010 1010 1110 1111 0010 0001(2)

5. Positive number before normalization:

0.000 020 830 729 321 671 205 134 999 154 509 660 631 7(10) =


0.0000 0000 0000 0001 0101 1101 0111 1011 0100 1101 0001 1010 1010 1110 1111 0010 0001(2)

6. Normalize the binary representation of the number.

Shift the decimal mark 16 positions to the right, so that only one non zero digit remains to the left of it:


0.000 020 830 729 321 671 205 134 999 154 509 660 631 7(10) =


0.0000 0000 0000 0001 0101 1101 0111 1011 0100 1101 0001 1010 1010 1110 1111 0010 0001(2) =


0.0000 0000 0000 0001 0101 1101 0111 1011 0100 1101 0001 1010 1010 1110 1111 0010 0001(2) × 20 =


1.0101 1101 0111 1011 0100 1101 0001 1010 1010 1110 1111 0010 0001(2) × 2-16


7. 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 0 (a positive number)


Exponent (unadjusted): -16


Mantissa (not normalized):
1.0101 1101 0111 1011 0100 1101 0001 1010 1010 1110 1111 0010 0001


8. Adjust the exponent.

Use the 11 bit excess/bias notation:


Exponent (adjusted) =


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


-16 + 2(11-1) - 1 =


(-16 + 1 023)(10) =


1 007(10)


9. 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;
  • 1 007 ÷ 2 = 503 + 1;
  • 503 ÷ 2 = 251 + 1;
  • 251 ÷ 2 = 125 + 1;
  • 125 ÷ 2 = 62 + 1;
  • 62 ÷ 2 = 31 + 0;
  • 31 ÷ 2 = 15 + 1;
  • 15 ÷ 2 = 7 + 1;
  • 7 ÷ 2 = 3 + 1;
  • 3 ÷ 2 = 1 + 1;
  • 1 ÷ 2 = 0 + 1;

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

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


Exponent (adjusted) =


1007(10) =


011 1110 1111(2)


11. 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. 0101 1101 0111 1011 0100 1101 0001 1010 1010 1110 1111 0010 0001 =


0101 1101 0111 1011 0100 1101 0001 1010 1010 1110 1111 0010 0001


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

Sign (1 bit) =
0 (a positive number)


Exponent (11 bits) =
011 1110 1111


Mantissa (52 bits) =
0101 1101 0111 1011 0100 1101 0001 1010 1010 1110 1111 0010 0001


Decimal number 0.000 020 830 729 321 671 205 134 999 154 509 660 631 7 converted to 64 bit double precision IEEE 754 binary floating point representation:

0 - 011 1110 1111 - 0101 1101 0111 1011 0100 1101 0001 1010 1010 1110 1111 0010 0001


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