Skip to content
MeerkatSkool Afrikaans
Summaries · Grade 4 Natural Sciences › Structures
Free summary · Grade 4 Natural Sciences

Structures

Frame, shell and solid structures, and what makes a structure strong and stable. Read one part at a time and tap “I know this”. Then test yourself in the quiz.

Know it already? Jump straight to the quiz

Your progress0 of 5

Kinds of structures

KindNatural exampleMan-made example
FrameSkeleton, spider webPylon, tent, bridge
ShellEggshell, tortoise shellDome, helmet
SolidRock, termite moundBrick wall, dam

An eggshell is strong for its thickness, because the curved shape spreads the pressure. A brick wall is strong, because the bricks overlap.

Tap when you could tell someone without looking.

Strong and stable

Square: wobbles and foldsWith a brace: two triangles, rigid
A diagonal brace turns a square into two strong triangles.
  • A bridge’s sides are often built with triangles.
  • Tent poles stand at an angle, and guy ropes pull the tent tight and steady.
  • A roof has a slope, so that rainwater can run off.
  • If the ground under a wall sinks unevenly, the wall cracks.
Frame structure
A frame structure: bars in triangles.
Tap when you could tell someone without looking.

Try it yourself

Stand a paper tube upright and put weight on it: it holds a lot of weight. A bridge collapses if the weight is heavier than it can carry.

Tap when you could tell someone without looking.

Make paper strong

  • Fold paper into hollow pillars: round, triangular or square. Test which one can carry the most books, and draw a bar graph of the results.
  • Roll paper into long, thin tubes: these are struts. Join the struts with sticky tape or paper split pins.
  • Struts joined in triangles make a strong, stable frame.
Tap when you could tell someone without looking.

Shelters for animals

  • Animals need shelter to stay safe from bad weather and predators, to sleep, and to lay eggs or raise their young.
  • Natural shelters (made or found by animals): a bird’s nest, a burrow in the ground (meerkat, mole), a bees’ nest with wax cells, a spider web, a termite mound, a cave or a hollow tree.
  • Human-made shelters (built by people for animals): a dog kennel, a wooden beehive box, a chicken coop, a pigsty, a stable, a birdhouse.
Rule

When you design a shelter, think about its purpose, shape, size and materials (strong, waterproof, warm).

Tap when you could tell someone without looking.

Remember this and test yourself

Remember this: your summary
  • A frame structure is built from bars (a pylon); a shell structure has a hard outer shell (an egg).
  • The triangle is the strongest shape: it keeps a frame rigid.
  • A wide, heavy base makes a structure stable, like a pyramid.
  • A foundation spreads the weight into the ground; a beam carries weight from above.
  • Fold or roll paper and it becomes stronger; a tube is stronger than a flat sheet.

Write these points in your book. Read them again the night before the test.

Memory trick

Frame = skeleton, shell = egg, solid = brick. And the triangle is the boss of strength.

Flash cards · Tap to turn over

Important words

First say what the word means, then turn the card over.

Test yourself · Part 2

True or false?

Read the question and the answer. Is the answer right? Tap True or False.

    Now the real quiz!

    The quiz has many more questions on this topic. Every question shows straight away whether you are right and explains why.

    Take the quiz: Structures
    All Grade 4 Natural Sciences summaries
    For parents
    • Read one part together and ask your child to tell it back in their own words.
    • The ticks (“I know this”) are saved on this device only. We never ask for names or emails.

    Follows CAPS for Grade 4 Natural Sciences and Technology. Always check your teacher’s notes and textbook too.

    Free PDF