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Solid shapes
Textbook Part 4, pp. 36–37
GoalName solid shapes, group them by properties and imagine views from different sides.
New words
sphere · sharcube · kubpyramid · piramidacuboid · kuboidcylinder · silindrcone · konus
Explanation
Solid shapes can be put in two groups: ones that roll (sphere, cylinder, cone) and ones that don’t (cube, cuboid, pyramid). Looking at a solid from different sides shows different flat shapes: a cylinder from the side is a rectangle, from above a circle.
Worked examples
Of 28 shapes, 14 are spheres, 3 cubes and the rest pyramids: 28 − 14 − 3 = 11 pyramids.
A wire square with 3 dm sides uses 3 + 3 + 3 + 3 = 12 dm of wire. Bent into an equilateral triangle, each side is 4 dm (4 + 4 + 4 = 12).
Class activity
Match classroom things to solids: ball — sphere, glass — cylinder, box — cuboid… Children sort them into “rolls / doesn’t roll”.
Practice
1
28 shapes: 14 spheres, 3 cubes, the rest pyramids. How many pyramids?
11
2
What do you see looking down on a cone?
A circle (with a point in the middle)
3
How many faces does a cube have?
6
4
Which roll: cube, sphere, cylinder?
The sphere and the cylinder