1. **State the problem:** We have a rectangle divided into small squares, each with an area of $9$ cm$^2$. The rectangle has $5$ squares in height and $6$ squares in width, so there are a total of $5 \times 6 = 30$ small squares. 2. **Calculate total area of the rectangle:** Since each small square has area $9$ cm$^2$, the total area of the rectangle is $$30 \times 9 = 270 \text{ cm}^2.$$ 3. **Calculate shaded area:** There are $16$ shaded squares, so the shaded area is $$16 \times 9 = 144 \text{ cm}^2.$$ 4. **Calculate unshaded area:** The unshaded area is the total area minus the shaded area: $$270 - 144 = 126 \text{ cm}^2.$$ **Final answer:** The area of the rectangle that is unshaded is $126$ cm$^2$.