Why do this problem?
This problem offers a simple challenge using logic gates and
circuits. Through experimentation with switches and settings,
students will begin to see the structure of logic gates emerge
without the need for any detailed formalism. They can then move on
to construct circuits with more complicated behaviours.
If students haven't worked with logic gates before you could
start by directing them to Circuit
Put the problem on to the board. Ask students to work out what
the circuit board does.
Encourage experimentation with combinations of on / off
switches and different settings on the logic gates. At each stage,
encourage students to predict what they think will happen, and to
explain what does happen.
Describe what you see.
What can we change?
What will happen if we change the settings?
Once the concept of the gate is understood there are several follow
up problems, such as Adding
You might suggest focussing on the AND and OR gates to begin