1. Structures

2. A structure is something that humans and animals build to be strong and stable. We also build structures to keep out the forces of natures, such as wind, rain, and snow.

3. Houses, bridges, tunnels, stores, and schools are all types of structures. These structures provide shelter and safety.

4. Bikes, trains, buses and planes are structures too. These structures help us to travel.

5. Stable Structures (Stability)

6. Structures that are stable are not likely to fall down or break when forces are applied to them. more stable less stable

7. Which stack of books looks the most stable? Why do you think so? A.B.

8. Have you ever tried to ride a bike? Your bike was probably very unstable. You may have fallen many times! How can you make a bike more stable, so that it is easier to ride?

9. An adult can hold on to you so that you don’t fall over. You can put extra wheels on the sides of your bike. These are called training wheels.

10. Three Little Pigs. Think about which house is more stable, and why.

11. Look at the following structures. Why do you think it is important that they are stable?

12. The C.N. Tower

13. A chair

14. A ladder

15. Strong Structures (Strength)

16. Structures must be strong so that they can hold weight and not change their shape.

17. Do you think one piece of paper rolled in a cylinder is strong enough to balance a math book? Let’s see!

18. These children are jumping on a bed. If the bed was not strong, it would break. The children could get very hurt.

19. Cars drive over bridges to cross water. What could happen if this structure was not strong?

20. What could happen if this house was not strong enough to hold the snow on the roof?

21. Look at the following structures. Why do you think it is important that they are strong?

22. couch sofa

23. bird nest

24. roller coaster track

25. stairs

26. To make structures strong and stable, builders often use one special shape… http://www.pbs.org/wgbh/buildingbig/lab/shapes.html Can you guess what the special shape is?

38. Can you find shapes in these famous structures around the world?

39. Taj Mahal - India

40. Sydney Opera House - Australia

41. Burj Al Arab hotel - Dubai

42. The Eiffel Tower - France