AQA A2 Computing 3.1 Real Numbers

Question 1

Real number

Answer 1

A number with a fractional part.

Question 2

Significant digits

Answer 2

The digits that carry meaning contributing accuracy to a number. This includes all digits except leading and trailing zeros where they serve merely as placeholders to indiciate the scale of a number.

Question 3

Floating-point notation

Answer 3

A real number represented by a sign, some significant digits, and a power of 2.

Question 4

Scientific notation

Answer 4

A real number represented by a sign, some significant digits, and a power of 10.

Question 5

Precision

Answer 5

The maximum number of significant digits that can be represented.

Question 6

Absolute error

Answer 6

The difference between the actual number and the nearest representable value.

Question 7

Relative error

Answer 7

The absolute error divided by the actual number.

Question 8

Underflow

Answer 8

The value is too small to be represented using the available number of bits.

Question 9

Overflow

Answer 9

The value is too large to be represented using the available number of bits.

Question 10

Normalisation

Answer 10

Maximising precision for the number of bits.