📚 LessonGrade 4Lesson 1
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Make Water Safe to Drink

How to use: Download the PDF to print the worksheet. Then use this page to repeat activities and check answers.

Learning Objectives

  • 1Explain why unsafe water is dangerous and must be treated
  • 2Make water safe using the two steps — filter, then purify
  • 3Describe wild ways to purify water without modern gear
  • 4Explain why sea water must be distilled before drinking
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Mini Lesson

Your body can last about three weeks without food — but only about three days without water. So finding water is not enough: you have to make it SAFE. Dirty water carries germs too small to see, and they can make you very sick. The good news: if you know how, you can turn almost any water into safe water. It takes two jobs — first take the dirt out (filter), then kill the germs (purify).

🏪 The Shop Way (if you have gear)

  1. Pour the water through a cloth or a store-bought filter to take out the dirt.
  2. Boil it for one full minute (a rolling boil) to kill the germs, then let it cool. That is it.

🌿 The Wild Way (with only what nature gives you)

  • FIND it: rain, a running stream, or wipe dew off the grass at dawn. Moving water beats still water.
  • FILTER it: pour it through layers of grass, sand, and charcoal from your fire, then gravel. The charcoal grabs the dirt and the bad taste.
  • PURIFY it — you still must kill the germs. ROCK-BOIL: heat clean stones in your fire, then drop them into a wooden or bark bowl of water until it bubbles.
  • No fire? Build a SOLAR STILL: dig a hole, put a cup in the middle, cover it with plastic or a big leaf, and weigh the centre down with a pebble. The sun lifts clean water as vapour and it drips into your cup — leaving the dirt and even salt behind.
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Never drink water just because it LOOKS clean — the germs are invisible. And remember: filtering takes out the dirt but NOT the germs, so you must always purify too. Never drink sea water straight — the salt makes you thirstier and sicker. And never eat snow to get water; melt it first, or it steals your body heat.

The two jobs: filter, then purifyTwo jobs to make water safe1 · FILTERTake the DIRT outgrasssandcharcoalgravel2 · PURIFYKill the GERMSBoil it — or dropfire-hot stones into make it bubble
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🧠 Survivor’s Trick: no cup and no fire? Tie a clear plastic bag over a leafy green branch in the sun. The leaves “sweat” and clean water collects in the low corner of the bag — a drink straight out of a living tree.

Vocabulary
contaminated
Water that has germs, dirt, or poison in it that can make you sick.
filter
To pass water through layers like sand and charcoal to take the dirt out.
purify
To kill the invisible germs in water, usually by boiling it.
sediment
The mud, sand, and bits that float or sink in dirty water.
solar still
A covered hole that uses the sun to lift clean water and leave dirt and salt behind.
distil
To turn water to steam and catch it clean again — the way to make sea water drinkable.
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Guided Practice

Pick a word from the Trace menu and look carefully — after 3 seconds the ghost letters fade and you write the word from memory. Tap 🔁 Show again to bring the model back, or 🔍 Bigger for a fullscreen practice canvas.

Tracing Pad

Tip: Say each word aloud as you trace it.

Now type any 3 different words from the Trace menu above. Look back if you need to — this is typing practice, not a memory test.
1.
2.
3.
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Exercises

Sort what each treatment removes: does filtering, boiling, or distilling take it out?

Filtering takes it out (the dirt)

Only boiling takes it out (the germs)

Only distilling takes it out (the salt)

Put the steps to make dirty water safe in the correct order.

1
2
3
4
5

Pick the best answer for each question.

1. Why is dirty water dangerous, even when it looks clean?

2. What are the TWO jobs to make water safe?

3. Pouring water through sand and charcoal mainly...

4. After you have filtered the water, you STILL must...

5. In the wild with no pot, how can you purify water?

6. Why must you NEVER drink sea water straight?

7. To drink water from the sea, you must...

8. A solar still makes clean water by...

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Assessment

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