Strand A: Foundations of Language and Mathematics · Patterns, Shapes, Measuring and Sorting

Building, Matching Halves and Shape Puzzles

A9.3 A9.4 A9.5About 25 minutes

Learning goals

I can build with blocks and boxes and name the 3D figures I used.
I can find flat shapes on the faces of 3D figures.
I can put shapes together to make new shapes and pictures, and take them apart.
I can make a picture with matching halves.

Words to know

build
To put things together to make something, like a tower.

face
A flat part of a 3D figure. A face is a 2D shape.

put together, take apart
Joining shapes to make a new shape, or breaking a shape into smaller shapes.

matching halves
When one half is the same as the other half, like a mirror. Grown-ups call this symmetry.

Let's be builders!

Grown-up, read this out loud.

Builders use lots of shapes. A house might have a box for the walls, a triangle-shaped roof, and round windows.

Today you will build, look for shapes on your blocks, and make pictures with matching halves.

A small red house with a triangle-shaped roof, a round window near the top, and rectangle windows and a door. — This house has a triangle roof, a round window, and rectangle windows and door. How many shapes can you find? AI-generated image

Look closely at a block. The flat parts are called faces. Every face is a flat shape.

If you dip a block in paint and stamp it on paper, you can see the shape of the face!

Stamp a cylinder (a can) and you get a circle. Stamp a cube and you get a square.

Worked example

Let's trace a face

Trace around the bottom of a cereal box. What shape do you get?

Stand the box on a piece of paper.
Hold it still and trace around the bottom with a crayon.
Lift the box. Look at the shape you drew. Count the sides: 1, 2, 3, 4.

A rectangle. The bottom face of a cereal box is a rectangle.

Shape puzzles

We can put shapes together to make new shapes. We can also take shapes apart into smaller shapes.

Put 2 triangles together to make a square. Put 2 squares together to make a rectangle.

Pattern blocks are great for shape puzzles. A hexagon can be made in different ways: with 2 trapezoids, with 3 rhombuses, or with 6 triangles.

The same hexagon made two ways: 2 trapezoids, or 6 triangles.

Worked example

Let's cut a sandwich

Cut a square sandwich from corner to corner. What shapes do you get?

Start with a square sandwich (or a square of paper).
Cut from one corner straight across to the opposite corner.
Look at each piece. Count the sides: 3 sides each.

You get 2 triangles. Push them back together and you have the square again!

Matching halves

Some things have two halves that match. If you fold them down the middle, one half lands right on top of the other half.

A butterfly's wings match. Your face is almost the same on both sides!

The dotted line goes down the middle. The two halves match on each side.

Hands-on activity

Builder's challenge and paint butterfly

Build: Use blocks or clean recycling (boxes, cans, tubes) to build a tower or a house. Then name the 3D figures you used: "I used a box, a can and a cone."

Paint butterfly:

Fold a paper in half and open it.
Put a few blobs of paint on one side only.
Fold it closed and press gently.
Open it. Both halves match!

Talk about it: "How do you know the halves match?"

Just for fun

What did one half of the sandwich say to the other half?

"Together, we make a perfect match!" 🥪

Your turn

Trace the bottom of a soup can. What shape do you get?

Stamp one face of a cube block in paint. What shape is the print?

Cut a square of paper from corner to corner. What 2 shapes do you get?

Put 2 same-size squares side by side. What shape do they make?

Look at the hexagon pictures. How many trapezoids make the hexagon? How many triangles?

🦋

Does a butterfly have matching halves?

Build a tower with 3 different blocks or boxes. Name the figures you used.

More practice: warm-up

Which has matching halves: ❤️ or 🐌?

What shape is the bottom face of a cereal box?

Does a ball (sphere) have a flat face to stamp?

Fold a square of paper in half, edge to edge. Do the halves match?

Name a block that is good for stacking.

More practice: on your own

What shape is the flat bottom of a cone?

Cut a square of paper in half, straight across from one side to the other. What 2 shapes do you get?

Which letter has matching halves when you fold it down the middle: A or F?

Draw half of a house. Ask a grown-up to draw the matching half.

How can 4 small triangles make 1 big triangle?

Challenge

How many same-size squares do you need to make one bigger square?

A tower has a box on the bottom, a can in the middle and an ice cream cone shape on top. Name each 3D figure.

Build a rocket or a house with matching halves using blocks or paper shapes. How can you check?

Check your understanding

Quiz

Trace the bottom of a can. What shape do you get?

Put 2 triangles together like a sandwich cut corner to corner. What can they make?

Which one has matching halves?

Stamp a cube in paint. What shape will the print be?

How many trapezoids put together make a hexagon?

For parents and teachers

What this is about: Children build with 3D figures and find the 2D shapes on their faces. They put shapes together and take them apart (composing and decomposing), and they explore matching halves (symmetry).

How to help at home:

Build with blocks, boxes and cans from the recycling. Ask your child to name the figures.
Stamp or trace faces of objects to see the flat shapes.
Cut sandwiches, toast or paper into shapes and put them back together. If you have pattern blocks (or paper cut-outs of them), make hexagons in different ways.
Look for matching halves in nature (leaves, butterflies) and in letters.

Common difficulties:

Mixing up the 3D figure and its face (calling a cube a "square"). Say: "The cube is the block. Its faces are squares."
Matching halves need the same size and shape in the same spot. Folding paper is the best way to check.