Make Thirds — Partition Shapes into 3 Equal Parts (Grade 2)

About this activity

A circle, triangle, hexagon, square, rectangle, diamond, or ellipse appears, and the child taps the cutting lines to divide it into three equal pieces — thirds. It's a free, interactive Grade 2 geometry activity that runs in the browser on any device, with nothing to install and no account.

The big idea is that thirds are trickier than halves because three equal pieces do not fall on an obvious middle line. A circle is split with three lines from the center, a rectangle into three equal strips, a triangle into three matching parts — so the child learns that 'thirds' means three same-size shares however the shape is cut. Making the cuts themselves builds the feel for equal partitioning that just looking at a picture cannot.

It is aligned to Common Core 2.G.A.3 — partitioning circles and rectangles into two, three, or four equal shares and describing the shares using the word thirds. No timer, no score — just calm, playful practice.

What's inside this activity

• Designed for Grade 2 learners (ages about 7–8)
• Common Core strand: Geometry
• Aligned to Common Core standard 2.G.A.3

How to play

Look at the shape you need to cut into 3 equal parts.

Tap the cutting lines to make thirds.

Check that the three pieces are equal — there is no timer and no score.

What your child practices

• Cutting a shape into 3 equal parts
• Making thirds across circles, rectangles, triangles, and more
• Keeping all three pieces the same size
• Using the word thirds for three equal shares

Learning goals

Partition shapes into three equal shares and name them thirds — the focus of Common Core 2.G.A.3

Understand that thirds must be three same-size parts, however the shape is cut

Strengthen the equal-partitioning sense that fractions build on