Introduction
CIE Floating Points
CIE Floating Point Numbers Representation
In the paper 3 exam, CIE floating numbers take on a slightly different, simplified version of floating point numbers that differs significantly from the international standard.
The CIE format is usually as follows:
- 8 Bits Mantissa:8 Bits Exponent
- Each 8 bits are in Two’s Complement form
- 1 at the start of the mantissa indicates a negative number
- 1 at the start of the exponent indicates a negative exponent
Example
10100101 11010110
Two’s compliment
01011011 00101010
Denary
0.1011011
Normalising
Normalising Floating Point Numbers
Over/Underflow
Binary Overflow
Binary Underflow
IEEE754
IEEE754 Floating Point Number International Standard
Note: This is not on the specification and you don’t need to know it for the exam but for general reference only.
Resources
Teacher Resources
CIE A Level Floating Point Representation Presentation
Past Paper Questions
- Nov 2015 31 Qn 1
- Nov 16 31 Qn 1
- June 18 31 Qn1
- Nov 18 31 qn2
- June 19 31 Qn1
- Nov 19 31 Qn1