Science 3

Matter is anything that takes up space and has weight: a rock, water and air are all matter, while a shadow, a sound and an idea are not.

Matter is the stuff everything around you is made of.

Processed materials are modified from natural materials and do not occur in nature: nobody finds a plastic bottle growing on a tree or a steel beam lying in a riverbed.

Natural materials, like wood, stone and wool, are found in nature.

The water cycle is the way water on Earth moves continuously between bodies of water, land and the air, with no beginning and no end.

The water cycle is drawn as a circle because it never stops.

A gas is matter even though it cannot be seen: air takes up space, so water cannot fill a cup pushed upside down into a tub, and air has weight.

Air is a gas, and you cannot see it, but it is still matter.

Processed materials are designed and manufactured for a specific purpose: steel is made strong for bridges, plastic light and waterproof for bottles, and glass clear for windows.

People make each processed material to do a job.

A force is a push or a pull on an object that comes from an interaction with another object, like a hand pushing a door.

A force always involves two things: something doing the pushing or pulling, and something being pushed or pulled.

The strength of a force can be described as strong or weak, large or small: a hard kick is a strong, large force and a gentle tap is a weak, small one.

Forces come in different strengths.

A simple machine reduces the effort needed to move an object: a ramp, a lever and a wheel all make heavy loads easier to move.

Effort is the push or pull you put in.

A push and a pull are both forces: pushing a wheelbarrow and pulling a sled both change how something moves.

A push moves something away from you and a pull moves it toward you, and both are forces.

A bigger push or pull makes an object move farther and faster: a toy car pushed hard rolls much farther than one pushed gently.

The harder you push or pull, the more an object moves.

Earth's surface is changing all the time, but most changes are too slow to watch: a mountain wears down over millions of years.

The land looks still, but it is always changing.

People change Earth's surface by living on the land and by building towns and cities, with roads, buildings and parking lots where there was once grass or forest.

Every house, road and school sits on land that used to look different.

Earth's surface contains layers deposited over long periods of time: mud, sand and other material settle one layer on top of another and slowly harden into rock.

Rivers, lakes, seas and wind lay down mud, sand and bits of plants and shells, one layer at a time.

Soil is a mix of rock particles, decaying plants and animals, living plants and animals, air and water.

Pick up a handful of garden soil and look closely.

Wind, water and ice move or remove material as they flow: a river carries sand downstream, wind blows dry soil, and a glacier drags rocks along.

Moving water picks up sand and pebbles and carries them downstream.

A food chain shows the order in which plants and animals depend on each other for food: grass is eaten by a grasshopper, the grasshopper by a frog, and the frog by a garter snake.

A food chain is a list of living things in the order they are eaten.

A stimulus is something in the surroundings that a living thing senses and responds to, such as water, food, temperature or light, and responding helps it survive.

Living things keep noticing what is around them.

Plants and animals depend on each other and their environments to survive, for food and for habitat: a red squirrel eats spruce seeds and nests in the spruce tree.

Nothing living manages on its own.

In a food chain diagram each arrow points from the food to the eater, so oak leaf, then caterpillar, then blue jay reads as 'the oak leaf is eaten by the caterpillar'.

Read every arrow as 'is eaten by'.

Plants respond to light by growing toward it: a plant on a windowsill bends toward the window, because the shaded side of its stem grows longer than the side facing the light.

Leave a bean plant on a windowsill for a few days and its stem bends toward the window.

Computational thinking is a way of solving problems that breaks a task into smaller chunks, finds patterns, picks out the important details, designs instructions and works backwards when a mistake is made.

Computer scientists use these five habits, and so can anyone.

The same outcome can be reached in different ways: one child walks to school, another takes the bus, and both arrive at school.

Outcomes and ways are different things.

Breaking a task into smaller chunks makes it easier: 'clean your room' becomes make the bed, put away clothes, pick up toys and sort books.

A big task can feel impossible, but small chunks are easy to start.

Divergent thinking is the process of coming up with many different, unique ideas or solutions, like listing ten different uses for a paper clip.

Divergent thinking means spreading your ideas out in many directions instead of stopping at the first one.

Finding patterns and similarities saves work: tying a second shoe is the same as the first, and a dance that repeats the same four moves can be written once.

When steps repeat, you only need to work them out once.

Accuracy of data is how correct a recorded observation is: writing 12 cm for a pencil that really is 12 cm long is accurate, and writing 15 cm is not.

Data are the observations you record: measurements, counts, drawings and notes.

Choosing appropriate tools and measuring carefully improve the accuracy of data: a thermometer, not a hand, measures how warm water is, and a ruler is read with its zero lined up at one end.

Your hand can tell that water feels warm, but not how warm, and two people's hands may disagree.

Objectivity is trying to remove the influence of personal thoughts, feelings and expectations, so that what someone hopes or expects to happen does not change what they record.

Say you are sure your paper airplane will fly farther than your friend's.

Measuring the same thing twice and getting the same answer is a check on accuracy: if a plant measures 8 cm and then 8 cm again, the measurement can be trusted.

Careful scientists measure more than once.

Data can come from many sources: investigations and personal observations, texts, websites, community members, and Elders or Knowledge Keepers.

Data is not only what you measure yourself.