A bar chart where each category has two bars instead of one. This is used when two frequencies exist for a category. This type of graph allows for comparisons to be made between the two sets of values.

# Category Archives: D

# Describe

Use words to explain what has happened.

Example: Describe, as a column vector, the translation of A to B.

πKey Topics: Reflection, Rotations, Translations, Enlargements

πAlso Look up: Describe Fully, Reflect, Rotate, Translate, Enlarge

# Describe fully

A command word that, when used in transformation questions is asking for:

If it is a reflection: A reflection in the line….(and then the equation of the mirror line)

If it is a translation: A translation by the vector…. (giving the vector). You may also say ‘A translation by ___ to the right and ___ up’.

If a rotation: A rotation _______(give clockwise/ anticlockwise) by _____(give the angle) about the centre _____ (give the coordinate of the centre).

In an enlargement: An enlargement of scale factor ____(give the scale factor) about the centre ___(give the centre of enlargement).

# Diameter

The distance between two points on the circumference of a circle, passing through the centre. It is equivalent to 2 lots of the radius.

Example:

π Key Diameter Topics: Parts of a Circle, Area of a Circle, Circumference of a Circle, Circle Theorems

πAlso Look Up: Circle, Radius, Sector

# Double

# Divisor

# Divisible

# Directed Number

A number that has a positive or a negative sign at the front of it.

Example: ^{–}2 or ^{+}7

π Key Directed Number Topics: Ordering Negatives, Negative Addition/Subtraction, Negative Multiplication and Division

# Direct Proportion

Where two values are linked by a common multiple. The key feature is that when you have none of one, you have none of the other.

Example: x and y are in direct proportion.Β

π Key Direct Proportion Topics: Direct and Inverse Proportion

# Difference

Another way of asking you to subtract two numbers.Β

Example: Find the difference of 8 and 17.Β

π Key Difference Topics: Subtraction, Negative Numbers