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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●000100010

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: 0010 = 2

  • 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●000100010
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: 0010 = 2

Subtracting the offset from the exponent value: -1

Normalised Exponent: 1111


Denary Value

Value: 0.25

MantissaExponent
0●100001111
Normalised

What is the Normalised Floating Point representation of the denary value 28

Mantissa

           

Exponent

               

Clue

Fixed Point Binary Value = 11100

Answer

Denary = 28

Fixed Point Binary Value = 11100

Mantissa = 011100

Exponent Value = 5

Exponent = 0101

MantissaExponent
0●111000101

The following is the binary floating point representation of a number

MantissaExponent
1●001011101

Calculate the denary equivalent of the number

Clue

Standard Form = -0.11011 x 2-3

MantissaExponent
-1
1
2
1
4
1
8
1
16
1
32
-8421
1●001011101

Answer

Exponent = 1101

Exponent Value = -3

Mantissa = 100101 (Two's Complement)

Mantissa = -011011 (Signed Value)

Standard Form = -0.11011 x 2-3

Fixed Point Binary Value = -0.00011011

Denary Value = -0.10546875

MantissaExponent
-1
1
2
1
4
1
8
1
16
1
32
-8421
1●001011101

The following is an approximate binary floating point representation of the number 0.2

MantissaExponent
0●110101110

Calculate the denary equivalent of the binary number

Clue

Standard Form = 0.11010 x 2-2

MantissaExponent
-1
1
2
1
4
1
8
1
16
1
32
-8421
0●110101110

Answer: Denary Equivalent

Exponent = 1110

Exponent Value = -2

Mantissa = 011010 (Two's Complement)

Standard Form = 0.11010 x 2-2

Fixed Point Binary Value = 0.001101

Denary = 0.203125

MantissaExponent
-1
1
2
1
4
1
8
1
16
1
32
-8421
0●110101110

Contents Copyright 2026 Andy Abraham

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