Free printable
Printable logic gates cheat sheet
A one-page logic gates cheat sheet. Each of the seven gates gets a card with its symbol, its truth table, its Boolean expression and the chip that holds it, so students can check a circuit row by row.
One page. Free to print and share for teaching. Print at actual size (100%), not fit to page. A4 suits most of the world; US Letter suits the USA and Canada.
What's on the sheet
- NOT, AND, OR, NAND, NOR, XOR and XNOR, one card each
- Both symbol styles: the distinctive (ANSI) shape and the IEC box
- A truth table for every gate, with the 1s picked out
- The Boolean expression, like Q = A · B, and when the output is 1, in words
- Chip numbers: the 74HC and 4000-series parts that hold each gate
- A key to the notation, bubbles and the universal gates
- Handy rules: De Morgan's laws, XOR from AND, OR and NOT, and the half adder
How to use it in class
Give it out before students build their first gate circuits, and ask them to fill in a blank truth table for a two-gate circuit using only the sheet. It also makes a good matching game: cut the cards apart, shuffle them, and have pairs match each symbol to its truth table. When they move to real chips, the part numbers tell them what to pick from the drawer.
Free lesson
Now build it yourself
Each lesson comes in three short parts: see the idea, try it on a live board, then build it yourself, with quick checks as you go.
“Logic gates” is lesson 2 of 6 in Logic Grid, Electronics World 7. Free with an account. Lessons unlock in order, so you’ll do the 43 before it first.
Or start from the very first lesson, no account neededThe charts online
Work it out
The ideas behind it
- Logic gates explainedAND, OR, NOT, XOR and their bubbled twins: each one's rule is a truth table.
- How to make a truth tableEvery input combination and its output: the complete, unarguable description of a logic circuit.
- Why is NAND called a universal gate?NOT, AND, OR and XOR from one kind of gate, and why chips love it.
- What is an XOR gate?1 when the inputs differ, 0 when they match: the gate behind stair lights, adders and parity bits.
Questions teachers ask
Which gate symbols does the sheet use?
The distinctive-shape symbols (ANSI), which most textbooks and simulators draw, with the rectangular IEC symbol beside each one: & for AND, ≥1 for OR and =1 for XOR. Both are correct, so students can recognise either.
How are NOT and NAND written as Boolean expressions?
With a bar over the part that's inverted. NOT A is A with a bar, and NAND is a bar over A · B. The sheet uses · for AND, + for OR and ⊕ for XOR.
Can I print it for a whole class?
Yes, it's free to print and share for teaching. One copy per student works well, as they'll refer to it all through a digital logic unit.
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