Skill: Partition shapes into thirds

To partition a shape into thirds, divide the whole shape into 3 parts that have the same area. Each part is called one third, written as $\frac{1}{3}$.

Example: Partition a rectangle into thirds.

1. Imagine the rectangle is made of $6$ equal columns and $2$ equal rows. It has $12$ equal squares altogether.
2. Share the $12$ squares equally among $3$ parts:

$$12 \div 3 = 4$$

So, each part must have $4$ squares. 3. Draw lines to make groups of $2$ columns. Each group has $2 \times 2 = 4$ squares.

$$\boxed{\begin{array}{|c|c||c|c||c|c|} \hline & & & & & \\ \hline & & & & & \\ \hline \end{array}}$$

The rectangle now has $3$ equal-area parts. Each part is $\frac{1}{3}$ of the whole rectangle.

Remember: Making three parts is not enough. The three parts must be equal in area.