Interactive Revision Tools

Step-by-step worked examples covering all Boolean algebra laws tested at A-Level. Reveal walkthroughs one step at a time and track which questions you have completed.

• Basic laws: idempotent, identity, null, complement, double negation
• De Morgan's law applied in both directions
• Multi-step algebraic simplification
• NAND and NOR gate equivalences
• Absorption law, including chained examples
• Progress saved automatically in your browser

Write and run real SQL queries against six different databases, all inside your browser. A full SQLite engine runs locally so nothing is ever sent to a server.

• Six scenarios: Cinema, Library, Hospital, Music, Football, School
• 48 guided exercises from basic SELECT to multi-table JOINs
• Auto-marked: get instant correct or incorrect feedback
• Hints and model solutions for every question
• Full DDL and DML coverage

Watch sorting algorithms run step by step with animated bar charts. Compare speeds, track comparisons and swaps, and understand exactly what each algorithm does at every stage.

• Bubble, Insertion, Selection, Merge, Quick Sort
• Play, Pause, and single-step controls
• Comparison and swap counters
• Time and space complexity shown for each algorithm

Convert between Binary, Denary, and Hexadecimal in any direction — with every step of the working shown. Not just the answer, but the complete method.

• All 6 conversion directions: Bin↔Den, Bin↔Hex, Den↔Hex
• Division method shown for Denary→Binary and Denary→Hex
• Positional value tables for Binary→Denary and Hex→Denary
• Direct 4-bit grouping method for Binary↔Hex

Push, pop, enqueue, and dequeue with live animation. See exactly how LIFO and FIFO structures behave side by side, with a full operation log.

• Stack (LIFO) with push and pop
• Queue (FIFO) with enqueue and dequeue
• Animated state updates with colour coding
• Overflow and underflow detection

Insert and delete values to build a BST. Watch the tree restructure in real time and animate in-order, pre-order, and post-order traversals node by node.

• Insert and delete with automatic restructuring
• Animated traversal - in-order, pre-order, post-order
• Tree height, balance, min, and max shown live
• Load a built-in example to explore immediately

Click cells to set 0s and 1s. Groups are found automatically, highlighted in colour, and the simplified Boolean SOP expression is shown instantly.

• 2, 3, and 4 variable K-maps
• Automatic grouping including wrapping groups
• Colour-coded group overlays on the map
• Truth table shown alongside the map

Step through algorithms line by line and fill in trace tables. Covers sorting algorithms, searching, and exam-style pseudocode questions.

• Bubble, Selection, Insertion Sort
• Linear and Binary Search, Merge Sort
• Fill-in-the-blank with auto-marking

Little Man Computer simulator with a visual accumulator, mailboxes, and step-through execution. Write and run LMC assembly programs in the browser.

• Full LMC instruction set with assembler
• Visual 100-mailbox memory display
• Step-through and run modes + examples

Click to place logic gates and connect them with wires. Signals propagate automatically and a truth table is generated from your circuit.

• AND, OR, NOT, NAND, NOR, XOR gates
• Live signal propagation (0/1)
• Auto truth table + Boolean expression