Grade 4 (age 9-10)

Fire and Safety

A fire needs three things together: fuel, oxygen, and heat above the ignition point. Take away any one and it goes out, so water cools a fire and a blanket blocks its oxygen. Remove each part of the fire triangle here and see how different tools put a fire out safely.

What does fire need?

🔥 3 Elements of Combustion

①Fuel: wood, paper, oil, etc.

②Oxygen: in the air

③Heat above ignition point: must be hot enough

④Remove any one and fire goes out

How to put out a fire

🧯 Extinguishing Principles

①Cooling: spray water to lower temperature

②Smothering: cover with blanket to block oxygen

③Removal: take fuel away

④Extinguisher: powder or gas puts fire out

Fire Evacuation Tips

🚨 When a fire breaks out

①Shout "Fire!" loudly

②Call 119

③Move low (smoke rises)

④Cover nose and mouth with a wet towel

⑤Use stairs, not the elevator

Summary

3 Elements of Combustion

Fire = Fuel + Oxygen + Heat above ignition

All three are needed for fire

Extinguishing Principle

Extinguish = remove one of the 3 elements

Cool (water) / Smother (blanket) / Remove (fuel)

Evacuation Principles

Low posture + wet towel + use stairs

Avoid smoke and evacuate safely

🎯 Key Points

①Combustion needs fuel + oxygen + heat

②Remove any one to extinguish

③Extinguisher: pin → nozzle → handle

④In a fire: call 119, evacuate low

⑤Always know your evacuation route

Examples and Unit Test

Example 1

A candle was covered with a glass cup and went out shortly after. Why did it go out?

For fire to burn, it needs fuel, oxygen, and a temperature at or above the ignition point.

The glass cup blocks the air, so no more oxygen gets in and the fire goes out.

▸ Because the oxygen was cut off (smothering)

If even one of the three elements of combustion is missing, the fire goes out.

Example 2

Why is water effective for putting out a fire on wood and paper?

When water touches fire it takes away heat, lowering the temperature below the ignition point.

When the temperature drops, the heat condition needed for burning is gone and the fire goes out (cooling).

▸ Because water lowers the temperature (cooling)

Water puts out fire by lowering temperature; a blanket does so by blocking oxygen.

Unit-test style

Which statement about putting out a fire is correct?

①Supplying more oxygen puts the fire out

②Removing the fuel puts the fire out

③Raising the temperature puts the fire out

④Combustion does not need oxygen

⑤Fire catches easily even below the ignition point

▸ ② Removing the fuel puts the fire out

Removing any one of the three elements (fuel, oxygen, heat) puts the fire out, so removing the fuel works (fuel removal).

Oxygen must be cut off, not added (①); temperature must be lowered (③); combustion does need oxygen (④); and fire only catches at or above the ignition point (⑤).

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