0.000 000 658 Converted to 32 Bit Single Precision IEEE 754 Binary Floating Point Representation Standard

Convert decimal 0.000 000 658(10) to 32 bit single precision IEEE 754 binary floating point representation standard (1 bit for sign, 8 bits for exponent, 23 bits for mantissa)

What are the steps to convert decimal number
0.000 000 658(10) to 32 bit single precision IEEE 754 binary floating point representation (1 bit for sign, 8 bits for exponent, 23 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: 0.000 000 658.

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) 0.000 000 658 × 2 = 0 + 0.000 001 316;
  • 2) 0.000 001 316 × 2 = 0 + 0.000 002 632;
  • 3) 0.000 002 632 × 2 = 0 + 0.000 005 264;
  • 4) 0.000 005 264 × 2 = 0 + 0.000 010 528;
  • 5) 0.000 010 528 × 2 = 0 + 0.000 021 056;
  • 6) 0.000 021 056 × 2 = 0 + 0.000 042 112;
  • 7) 0.000 042 112 × 2 = 0 + 0.000 084 224;
  • 8) 0.000 084 224 × 2 = 0 + 0.000 168 448;
  • 9) 0.000 168 448 × 2 = 0 + 0.000 336 896;
  • 10) 0.000 336 896 × 2 = 0 + 0.000 673 792;
  • 11) 0.000 673 792 × 2 = 0 + 0.001 347 584;
  • 12) 0.001 347 584 × 2 = 0 + 0.002 695 168;
  • 13) 0.002 695 168 × 2 = 0 + 0.005 390 336;
  • 14) 0.005 390 336 × 2 = 0 + 0.010 780 672;
  • 15) 0.010 780 672 × 2 = 0 + 0.021 561 344;
  • 16) 0.021 561 344 × 2 = 0 + 0.043 122 688;
  • 17) 0.043 122 688 × 2 = 0 + 0.086 245 376;
  • 18) 0.086 245 376 × 2 = 0 + 0.172 490 752;
  • 19) 0.172 490 752 × 2 = 0 + 0.344 981 504;
  • 20) 0.344 981 504 × 2 = 0 + 0.689 963 008;
  • 21) 0.689 963 008 × 2 = 1 + 0.379 926 016;
  • 22) 0.379 926 016 × 2 = 0 + 0.759 852 032;
  • 23) 0.759 852 032 × 2 = 1 + 0.519 704 064;
  • 24) 0.519 704 064 × 2 = 1 + 0.039 408 128;
  • 25) 0.039 408 128 × 2 = 0 + 0.078 816 256;
  • 26) 0.078 816 256 × 2 = 0 + 0.157 632 512;
  • 27) 0.157 632 512 × 2 = 0 + 0.315 265 024;
  • 28) 0.315 265 024 × 2 = 0 + 0.630 530 048;
  • 29) 0.630 530 048 × 2 = 1 + 0.261 060 096;
  • 30) 0.261 060 096 × 2 = 0 + 0.522 120 192;
  • 31) 0.522 120 192 × 2 = 1 + 0.044 240 384;
  • 32) 0.044 240 384 × 2 = 0 + 0.088 480 768;
  • 33) 0.088 480 768 × 2 = 0 + 0.176 961 536;
  • 34) 0.176 961 536 × 2 = 0 + 0.353 923 072;
  • 35) 0.353 923 072 × 2 = 0 + 0.707 846 144;
  • 36) 0.707 846 144 × 2 = 1 + 0.415 692 288;
  • 37) 0.415 692 288 × 2 = 0 + 0.831 384 576;
  • 38) 0.831 384 576 × 2 = 1 + 0.662 769 152;
  • 39) 0.662 769 152 × 2 = 1 + 0.325 538 304;
  • 40) 0.325 538 304 × 2 = 0 + 0.651 076 608;
  • 41) 0.651 076 608 × 2 = 1 + 0.302 153 216;
  • 42) 0.302 153 216 × 2 = 0 + 0.604 306 432;
  • 43) 0.604 306 432 × 2 = 1 + 0.208 612 864;
  • 44) 0.208 612 864 × 2 = 0 + 0.417 225 728;

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:


0.000 000 658(10) =


0.0000 0000 0000 0000 0000 1011 0000 1010 0001 0110 1010(2)

5. Positive number before normalization:

0.000 000 658(10) =


0.0000 0000 0000 0000 0000 1011 0000 1010 0001 0110 1010(2)

6. Normalize the binary representation of the number.

Shift the decimal mark 21 positions to the right, so that only one non zero digit remains to the left of it:


0.000 000 658(10) =


0.0000 0000 0000 0000 0000 1011 0000 1010 0001 0110 1010(2) =


0.0000 0000 0000 0000 0000 1011 0000 1010 0001 0110 1010(2) × 20 =


1.0110 0001 0100 0010 1101 010(2) × 2-21


7. Up to this moment, there are the following elements that would feed into the 32 bit single precision IEEE 754 binary floating point representation:

Sign 0 (a positive number)


Exponent (unadjusted): -21


Mantissa (not normalized):
1.0110 0001 0100 0010 1101 010


8. Adjust the exponent.

Use the 8 bit excess/bias notation:


Exponent (adjusted) =


Exponent (unadjusted) + 2(8-1) - 1 =


-21 + 2(8-1) - 1 =


(-21 + 127)(10) =


106(10)


9. Convert the adjusted exponent from the decimal (base 10) to 8 bit binary.

Use the same technique of repeatedly dividing by 2:


  • division = quotient + remainder;
  • 106 ÷ 2 = 53 + 0;
  • 53 ÷ 2 = 26 + 1;
  • 26 ÷ 2 = 13 + 0;
  • 13 ÷ 2 = 6 + 1;
  • 6 ÷ 2 = 3 + 0;
  • 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) =


106(10) =


0110 1010(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 23 bits, only if necessary (not the case here).


Mantissa (normalized) =


1. 011 0000 1010 0001 0110 1010 =


011 0000 1010 0001 0110 1010


12. The three elements that make up the number's 32 bit single precision IEEE 754 binary floating point representation:

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


Exponent (8 bits) =
0110 1010


Mantissa (23 bits) =
011 0000 1010 0001 0110 1010


Decimal number 0.000 000 658 converted to 32 bit single precision IEEE 754 binary floating point representation:

0 - 0110 1010 - 011 0000 1010 0001 0110 1010


How to convert decimal numbers from base ten to 32 bit single precision IEEE 754 binary floating point standard

Follow the steps below to convert a base 10 decimal number to 32 bit single 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 base ten 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 of the previous dividing 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 previous multiplying operations, starting from the top of the constructed list 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, by shifting the decimal point (or if you prefer, the decimal mark) "n" positions either to the left or to the right, so that only one non zero digit remains to the left of the decimal point.
  • 7. Adjust the exponent in 8 bit excess/bias notation and then convert it from decimal (base 10) to 8 bit binary, by using the same technique of repeatedly dividing by 2, as shown above:
    Exponent (adjusted) = Exponent (unadjusted) + 2(8-1) - 1
  • 8. Normalize mantissa, remove the leading (leftmost) bit, since it's allways '1' (and the decimal sign if the case) and adjust its length to 23 bits, either by removing the excess bits from the right (losing precision...) or by adding extra '0' bits 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 -25.347 from decimal system (base ten) to 32 bit single precision IEEE 754 binary floating point:

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

    |-25.347| = 25.347

  • 2. First convert the integer part, 25. Divide it repeatedly by 2, keeping track of each remainder, until we get a quotient that is equal to zero:
    • division = quotient + remainder;
    • 25 ÷ 2 = 12 + 1;
    • 12 ÷ 2 = 6 + 0;
    • 6 ÷ 2 = 3 + 0;
    • 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:

    25(10) = 1 1001(2)

  • 4. Then convert the fractional part, 0.347. 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) 0.347 × 2 = 0 + 0.694;
    • 2) 0.694 × 2 = 1 + 0.388;
    • 3) 0.388 × 2 = 0 + 0.776;
    • 4) 0.776 × 2 = 1 + 0.552;
    • 5) 0.552 × 2 = 1 + 0.104;
    • 6) 0.104 × 2 = 0 + 0.208;
    • 7) 0.208 × 2 = 0 + 0.416;
    • 8) 0.416 × 2 = 0 + 0.832;
    • 9) 0.832 × 2 = 1 + 0.664;
    • 10) 0.664 × 2 = 1 + 0.328;
    • 11) 0.328 × 2 = 0 + 0.656;
    • 12) 0.656 × 2 = 1 + 0.312;
    • 13) 0.312 × 2 = 0 + 0.624;
    • 14) 0.624 × 2 = 1 + 0.248;
    • 15) 0.248 × 2 = 0 + 0.496;
    • 16) 0.496 × 2 = 0 + 0.992;
    • 17) 0.992 × 2 = 1 + 0.984;
    • 18) 0.984 × 2 = 1 + 0.968;
    • 19) 0.968 × 2 = 1 + 0.936;
    • 20) 0.936 × 2 = 1 + 0.872;
    • 21) 0.872 × 2 = 1 + 0.744;
    • 22) 0.744 × 2 = 1 + 0.488;
    • 23) 0.488 × 2 = 0 + 0.976;
    • 24) 0.976 × 2 = 1 + 0.952;
    • We didn't get any fractional part that was equal to zero. But we had enough iterations (over Mantissa limit = 23) 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:

    0.347(10) = 0.0101 1000 1101 0100 1111 1101(2)

  • 6. Summarizing - the positive number before normalization:

    25.347(10) = 1 1001.0101 1000 1101 0100 1111 1101(2)

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

    25.347(10) =
    1 1001.0101 1000 1101 0100 1111 1101(2) =
    1 1001.0101 1000 1101 0100 1111 1101(2) × 20 =
    1.1001 0101 1000 1101 0100 1111 1101(2) × 24

  • 8. Up to this moment, there are the following elements that would feed into the 32 bit single precision IEEE 754 binary floating point:

    Sign: 1 (a negative number)

    Exponent (unadjusted): 4

    Mantissa (not-normalized): 1.1001 0101 1000 1101 0100 1111 1101

  • 9. Adjust the exponent in 8 bit excess/bias notation and then convert it from decimal (base 10) to 8 bit binary (base 2), by using the same technique of repeatedly dividing it by 2, as already demonstrated above:

    Exponent (adjusted) = Exponent (unadjusted) + 2(8-1) - 1 = (4 + 127)(10) = 131(10) =
    1000 0011(2)

  • 10. Normalize the mantissa, remove the leading (leftmost) bit, since it's allways '1' (and the decimal point) and adjust its length to 23 bits, by removing the excess bits from the right (losing precision...):

    Mantissa (not-normalized): 1.1001 0101 1000 1101 0100 1111 1101

    Mantissa (normalized): 100 1010 1100 0110 1010 0111

  • Conclusion:

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

    Exponent (8 bits) = 1000 0011

    Mantissa (23 bits) = 100 1010 1100 0110 1010 0111

  • Number -25.347, converted from the decimal system (base 10) to 32 bit single precision IEEE 754 binary floating point =
    1 - 1000 0011 - 100 1010 1100 0110 1010 0111