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Floating Point Binary

Floating Point Binary: Definition

Current size definition

Normalised floating point binary representation with a mantissa and exponent both in two's complement binary

Mantissa:6
Exponent:4

Valid range for positive values:
Binary:0.000000001 to 1111100
Denery:0.001953125 to 124

Valid range for negative values:
Binary:-0.000000001 to -10000000
Denery:-0.001953125 to -128

Change the size of the mantissa and exponent

Select the size of the mantissa

Select the size of the exponent


The following is the floating point representation of a number

MantissaExponent
0●000101011

The value is not normalised. What is the normalised form of this binary number?

Mantissa

           

Exponent

               

Clue

Mantissa: 000010

  • To calculate the new mantissa: shift the digits of the mantissa to the left until the first two characters are 01

Exponent: 1011 = -5

  • Offset = The number of places that the Mantissa is shifted to the left
  • To calculate the new exponent: subtract the offset from exponent value
MantissaExponent
0●000101011
Not Normalised

Mantissa Calculation

Original Mantissa: 000010

Normalised Mantissa: 010000

The digits are shifted to the left by 3

offset = 3


Exponent Calculation

Original Exponent: 1011 = -5

Subtracting the offset from the exponent value: -8

Normalised Exponent: 1000


Denary Value

Value: 0.001953125

MantissaExponent
0●100001000
Normalised

What is the Normalised Floating Point representation of the denary value 0.0390625

Mantissa

           

Exponent

               

Clue

Fixed Point Binary Value = 0.0000101

Answer

Denary = 0.0390625

Fixed Point Binary Value = 0.00001

Mantissa = 010100

Exponent Value = -4

Exponent = 1100

MantissaExponent
0●101001100

The following is the binary floating point representation of a number

MantissaExponent
0●100001000

Calculate the denary equivalent of the number

Clue

Standard Form = 0.10000 x 2-8

MantissaExponent
-1
1
2
1
4
1
8
1
16
1
32
-8421
0●100001000

Answer

Exponent = 1000

Exponent Value = -8

Mantissa = 010000 (Two's Complement)

Standard Form = 0.10000 x 2-8

Fixed Point Binary Value = 0.000000001

Denary Value = 0.001953125

MantissaExponent
-1
1
2
1
4
1
8
1
16
1
32
-8421
0●100001000

The following is an approximate binary floating point representation of the number 0.82

MantissaExponent
0●110100000

Calculate the denary equivalent of the binary number

Clue

Standard Form = 0.11010 x 20

MantissaExponent
-1
1
2
1
4
1
8
1
16
1
32
-8421
0●110100000

Answer: Denary Equivalent

Exponent = 0000

Exponent Value = 0

Mantissa = 011010 (Two's Complement)

Standard Form = 0.11010 x 20

Fixed Point Binary Value = 0.1101

Denary = 0.8125

MantissaExponent
-1
1
2
1
4
1
8
1
16
1
32
-8421
0●110100000

Contents Copyright 2026 Andy Abraham

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