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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
1●111001111

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

Mantissa

           

Exponent

               

Clue

Mantissa: 111100

  • To calculate the new mantissa: shift the digits of the mantissa to the left until the first two characters are 10

Exponent: 1111 = -1

  • 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
1●111001111
Not Normalised

Mantissa Calculation

Original Mantissa: 111100

Normalised Mantissa: 100000

The digits are shifted to the left by 3

offset = 3


Exponent Calculation

Original Exponent: 1111 = -1

Subtracting the offset from the exponent value: -4

Normalised Exponent: 1100


Denary Value

Value: -0.0625

MantissaExponent
1●000001100
Normalised

What is the Normalised Floating Point representation of the denary value 42

Mantissa

           

Exponent

               

Clue

Fixed Point Binary Value = 101010

Answer

Denary = 42

Fixed Point Binary Value = 101010

Mantissa = 010101

Exponent Value = 6

Exponent = 0110

MantissaExponent
0●101010110

The following is the binary floating point representation of a number

MantissaExponent
1●010010101

Calculate the denary equivalent of the number

Clue

Standard Form = -0.10111 x 25

MantissaExponent
-1
1
2
1
4
1
8
1
16
1
32
-8421
1●010010101

Answer

Exponent = 0101

Exponent Value = 5

Mantissa = 101001 (Two's Complement)

Mantissa = -010111 (Signed Value)

Standard Form = -0.10111 x 25

Fixed Point Binary Value = -10111

Denary Value = -23

MantissaExponent
-1
1
2
1
4
1
8
1
16
1
32
-8421
1●010010101

The following is an approximate binary floating point representation of the number 0.34

MantissaExponent
0●101101111

Calculate the denary equivalent of the binary number

Clue

Standard Form = 0.10110 x 2-1

MantissaExponent
-1
1
2
1
4
1
8
1
16
1
32
-8421
0●101101111

Answer: Denary Equivalent

Exponent = 1111

Exponent Value = -1

Mantissa = 010110 (Two's Complement)

Standard Form = 0.10110 x 2-1

Fixed Point Binary Value = 0.01011

Denary = 0.34375

MantissaExponent
-1
1
2
1
4
1
8
1
16
1
32
-8421
0●101101111

Contents Copyright 2026 Andy Abraham

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