I Sense, I Think, I Signal

1. What your child learns and why

Your child learns that a sensor only senses, the system's “brain” (the control panel) compares with a rule, and the signal — sound, light or a message — is for people, so they can act calmly. In the game your child sets a threshold with game numbers, and older children compare the rules AND / OR for two sensors. This is a first step towards logic and programming. The lesson deliberately does not talk about burglars or fires.

2. Three questions for dinner

• “What does the sensor notice, and what does the brain do?”
• “Which signal at home works by a rule?” (The alarm clock, the oven timer, the traffic light.)
• “If the signal rang for every little thing, what would happen with people?” (They would stop paying attention.)

3. 15 minutes together, no screen — the living chain

1. Share out the roles: sensors, brain, siren, people. Your child chooses and may watch first.
2. The group writes a rule, e.g. “a signal when at least one sensor raises a hand”. The leader shows slips “smoke” / “nothing”; the brain checks the rule and touches the siren.
3. The siren claps twice, the people walk calmly to the door. Swap roles and change the rule.

4. What success looks like

• Your child tells the four-step chain and gives an example of a rule.
• In the game your child sets the threshold so that “very little” stays quiet and “a lot” gives a signal.

5. Common difficulties

• Thinks the sensor decides by itself → “The sensor only says what it notices. The brain decides — by the rule.”
• Wants the threshold very low “to be safe” → “Then the signal rings without need. Let's find the middle.”

Say: “You are the engineer — you write the rule.” Avoid stories about burglars and fires, and comparisons with other children.

6. Safety

In the living chain the siren claps, it does not shout; everyone walks, nobody runs; play in a clear space. Real sensors and buttons are not touched. Whether your home has a smoke alarm and how it sounds is a matter for the adults; the London Fire Brigade reminds us that a smoke alarm detects smoke and a heat alarm detects a rapid rise in heat.

7. Where to go next

Next lesson: DB-PZ-03 “The Camera's Eye”. Previous: DB-PZ-01 “The Building's Senses”. For more circuits and thresholds in the library: “What Is Current? A Closed Circuit” (DB-EL-01), “AND, OR, NOT: Logic Gates” (DB-EL-03) and “Night Light: Sensor + LED” (DB-EL-05).

You don't need to know the answer. Say: “Let's find out together.”