C
- Calendar
- Capacity
- Cardinality
- Carroll diagram
- Casework
- Categorical data
- Categorical variable
- Category
- Causation
- Census
- Centimetre
- Centre
- Certain event
- Chance
- Change
- Chart
- Checking a solution
- Chord
- Circle
- Circumference
- Classification
- Clockwise
- Closure property
- Coefficient
- Colon
- Column
- Column addition
- Column subtraction
- Combination
- Combinatorics
- Common difference
- Common factor
- Common multiple
- Common ratio
- Commutative property
- Comparison
- Comparison bar model
- Compensation
- Complement of a set
- Complement of an event
- Compose a number
- Compose shapes
- Composite number
- Composite shape
- Compound event
- Compound unit
- Conclusion
- Concrete model
- Conditional probability
- Cone
- Congruent figures
- Conjecture
- Conjunction
- Consecutive numbers
- Constant
- Constant of proportionality
- Constant term
- Constraint
- Constraint satisfaction
- Continuous data
- Contradiction
- Coordinate
- Coordinate distance
- Coordinate path
- Coordinate plane
- Correlation
- Count back
- Count on
- Counterexample
- Counting
- Counting number
- Cross-section
- Cube
- Cube number
- Cube root
- Cubic centimetre
- Currency notation
- Currency symbol
- Curriculum standard
- Cylinder