Lesson Plan

• Describe the function of the six basic Boolean operators (AND, OR, NOT, XOR, NAND, NOR).
• Apply a systematic procedure to construct truth tables from logical expressions.
• Build truth tables for combinational circuits by identifying inputs, intermediate gate outputs, and final results.
• Analyse truth‑table results to recognise contradictions, tautologies and to verify correctness.
• Use exam‑focused techniques (alphabetical variable order, binary counting, intermediate columns) to avoid common errors.

• Projector and screen
• Whiteboard and markers
• Printed worksheets with practice expressions and circuit diagrams
• Truth‑table template handouts
• Circuit diagram cards (AND, OR, NOT, NAND, NOR, XOR)
• Calculators (optional)

Begin with a quick poll: “What everyday decisions are based on ‘yes’ or ‘no’ choices?” Connect this to Boolean true/false logic. Review that students already know the meaning of AND, OR and NOT from previous lessons. State that by the end of the lesson they will be able to create accurate truth tables for both expressions and simple circuits, a key requirement for the IGCSE exam.

1. Do‑now (5'): Students complete a 2‑variable truth table on the board to refresh basic operator rules.
2. Mini‑lecture (10'): Review all six Boolean operators and the step‑by‑step method for building a truth table from an expression; demonstrate with $(A∧B)∨¬C$.
3. Guided practice (12'): In pairs, students construct the truth table for $¬(A∨B)∧(A⊕B)$ using the worksheet, with teacher circulating for questions.
4. Circuit modelling (10'): Show a three‑gate circuit (AND, NOT, OR). Students identify inputs, label intermediate columns (D, E) and fill the table row‑by‑row.
5. Independent practice (5'): Students complete the NAND/NOR circuit question on their own.
6. Exit ticket (3'): Each student writes one exam tip for truth‑table creation (e.g., “list variables alphabetically”).

Recap the five‑step procedure for expressions and the parallel steps for circuits, highlighting the importance of intermediate columns. Collect exit tickets to gauge understanding. For homework, assign three additional truth‑table problems (two expressions, one circuit) to reinforce the day’s learning.