math · STEAM

Monday Math- 3D shapes

While I typically try to tie the math activity into the weekly topic, today I’m going off on a tangent. Today we will work on 3D, or solid, shapes. The recognition and labeling of 3D shapes is a preK skill that will get addressed again in K and 1st grade, each time adding more information to the skill.

3D shapes are labeled and recognized by the shape and size of their faces. We learn to count and identify the number and type of faces on the shapes. A cube is created of 6 square faces, where a cylinder has 2 circular faces and a curved rectangle face. A pyramid has 3 triangular faces and one square face.

We then learn to count the edges, this is where the sides of each shape meet. A cube has 12 edges and a cylinder has 2.

Finally we look at the number of vertices. We leaned this word discussing 2D shapes. The vertices are where the two sides of a 2D shapes or a combination of edges on a 3D shape meet.

(The most important thing to focus on is being able to identify items that represent each of the 3D shape labels…. a can is a cylinder, a cereal box is a rectangular prism)

This video will help introduce 3D shapes to your child.

3D shapes can be found all around us. Have your child find items around the house that are cylinders, cubes, rectangular prisms, and spheres. Remember 3D shapes have length, width and height, so they cannot be flat.

pyramid made with Craisins and toothpicks

Finally allow your child to construct his/her own 3D shapes. A fun way to do this is to use food/play dough and toothpicks/straws to build the shapes. In school we do this with marshmallows or clay and toothpicks. Using straws allows you to alter the length and make the rectangular shapes more precisely, but you need a larger item to push them into. Using wooden skewers and toothpicks allows for this same effect, but just be careful of poking with the skewers are they are pointier than toothpicks.

In school, we will work at the same time to make a cube and then I allow them to explore. One of the best things to do is sit there and make a shape yourself. You will be surprised at how creative they can be and when they see you working on it too they will gain some strategies on how to make it work.

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