Germ Spread Sim

Hook 5 min

1. "Raise your hand if you've ever caught a cold from someone. Did you know they were sick when you caught it?"
2. Introduce the class on screen: 24 students, and one (the dashed circle) came to school with cold germs but feels fine.
3. Students predict how many of the 24 will catch the cold in two weeks. Write the predictions on the board.

Explore 15 min

1. Press Start 2 weeks with no habits on. Watch the coughs (green puffs), the shared door handle and the crayon bin. Record the number sick (usually about 20).
2. Pairs choose one habit to test: wash hands, Cover coughs (into elbow), Stay home when sick, or wipe shared things. Then Run again. The same student brings the same germs, so the test is fair.
3. Pairs add their result to the board. Then try two habits together.
4. Last run: turn on all four. (It usually stops at the first student.)

Make sense 10 min

1. "Why didn't anyone know the first student was sick?" (People can spread germs the day before they feel sick.)
2. Read the board. "Which habit helped the most? Which is easiest to do?"
3. "Washing sometimes barely helped. Why?" (One missed wash before snack is enough.)
4. "Coughing into your hand blocks the spray. Why is the elbow better?" (Your hands carry the germs to everything you touch.)
5. Remind the class this is a simple model of one classroom, not a medical prediction.

Apply 10 min

1. Switch to Wash up. A volunteer does the five steps: wet, soap, scrub, rinse, dry. Scrubbing counts real seconds toward 20. Use Turn hand over for the back.
2. The black light shows what was missed. "Where do germs hide?" (Thumbs, between fingers, under nails.)
3. Try water only to see how much soap matters.
4. If you can, go to the sink: everyone practices the five steps while humming for 20 seconds.

Exit check 5 min

On a card: name two ways germs spread in a classroom, and the one habit you'll use most, with a reason. Cards that don't mention spreading before feeling sick show what to revisit.