Shape attributes, halves, and fourths (grade 1) · lesson

What makes a shape

💡 Sides and corners name a shape. Color and size do not.

Every triangle has 3 sides and is closed. It can be red or blue, big or small.

A shape with 4 sides and 4 square corners is a rectangle.

🧠 How to think about it

Ignore the color and the size. Count the sides and corners. Then name it.

🏡 Try it at home

Make triangles with straws or sticks. Make a big one and a small one. Both are triangles!

💡 Shapes can join to make new shapes.

2 squares side by side make a rectangle.

6 triangles can fit together to make a hexagon.

🧠 How to think about it

Put the shapes together in your head. Count the sides of the new outside edge.

🏡 Try it at home

Cut two paper squares. Put them side by side. What shape do they make?

💡 Equal shares are parts that are all the same size.

Cut a cake in 2 same-size parts. Those are halves.

If one piece is much bigger, they are not halves.

🧠 How to think about it

Look at each part. Are they the same size? Then they are equal shares. Count them to name them.

🏡 Try it at home

Fold a paper napkin in half. Open it. Are the parts the same size?

💡 More equal shares means each share is smaller.

2 halves make a whole. 4 fourths make a whole.

A fourth is smaller than a half of the same pizza.

🧠 How to think about it

Sharing with 1 friend gives big halves. Sharing with 3 friends gives small fourths.

🏡 Try it at home

Cut a sandwich in halves. Cut another in fourths. Which pieces are bigger?