Grade 4 · Unit 2: Living things and environments

Wonderful water

All life needs water – clean water.

Plants, animals and people all need water to live.

Water for life

Every living thing needs water. Your body is more than half water. You lose water when you sweat, breathe out and go to the toilet. Plants need water to make food and stay upright.

A person can live for weeks without food but only a few days without water. In hot weather, children should drink water often, even before they feel thirsty.

Where our water comes from

Most of the Earth’s water is salty sea water. We need fresh water from rivers, ponds and underground. Many families in Bangladesh pump water from a tube well.

Rainwater can also be collected from roofs and stored in tanks. Many coastal families, where the ground water is salty, rely on rainwater for drinking.

Is it safe?

Water can look clean but still contain germs or poisons. In some places, underground water contains arsenic, a poison. Tube wells are tested. Green ones are safe; red ones are not safe for drinking.

Water can be made safer to drink by boiling it, using a filter, or adding special tablets. These ways purify the water.

Saving water

Clean water is precious. Do not waste it. Turn off taps when you brush your teeth. Fix dripping taps. Collect rainwater to water plants.

A dripping tap can waste more than 10 litres of water a day. Using a bucket instead of a running hose to wash a car saves hundreds of litres.

What I learnt