In deductive reasoning, general principles are applied to specific instances. If the original premises are true, conclusions based on deductive reasoning are also true. For example:
Even numbers are integers that can be arranged as pairs.
I can arrange six blocks as three pairs.
So six is an even number.
Applying a rule, formula or theorem is a form of deduction.
The sum of the angles of any triangle is 180°.
This shape is a triangle.
The sum of its angles is 180°.
Max's Statements is an activity involving deduction to try with students from years 5–9.