Shapes and equal shares: halves, thirds, fourths (grade 2) · lesson

Name shapes by sides

💡 Count the sides or angles to name a flat shape.

3 sides is a triangle. 4 sides is a quadrilateral. 5 is a pentagon. 6 is a hexagon.

A square and a rectangle both have 4 sides. They are quadrilaterals.

🧠 How to think about it

Count the sides. Then match the number to the name. Quad means four.

🏡 Try it at home

Find a stop sign, a window, and a slice of pizza. Count each shape's sides.

💡 A face is a flat side of a solid shape.

A cube has 6 square faces: top, bottom, and 4 sides.

A cylinder has 2 round faces. A square is flat, so it has no faces.

🧠 How to think about it

Hold the shape. Touch each flat side once and count.

🏡 Try it at home

Count the faces on a box and on a die. Do they match?

💡 Count the equal parts to name them, then count the shaded parts.

3 equal parts are thirds. 4 equal parts are fourths.

If 3 of 4 parts are shaded, that is three fourths.

🧠 How to think about it

First count all the equal parts. That gives the name. Then count how many are shaded.

🏡 Try it at home

Cut a pancake into thirds. Eat one. How many thirds are left?

💡 More equal parts of the same whole means each part is smaller.

2 halves, 3 thirds, or 4 fourths each make one whole.

A half is bigger than a third. A third is bigger than a fourth.

🧠 How to think about it

Picture one pie shared by 2, 3, or 4 people. More people means smaller pieces.

🏡 Try it at home

Fold three paper strips into halves, thirds, and fourths. Compare the pieces.

💡 Equal shares of the same whole are the same size, even if they look different.

Cut one square into 2 rectangles. Cut the same size square into 2 triangles.

Both are halves of the same square. So they are the same size.

🧠 How to think about it

Ask: are these parts of the same whole, cut into the same number of equal parts? Then they match.

🏡 Try it at home

Cut two same-size pieces of toast in half two different ways. Are the halves the same?