The area of the region bounded by the curve $y = f (x)$ and the ordinates $x = a, x = b$ is given by Area $= \left|\int\limits^{b}_{a} y\, dx\right|$ According to the question, $y =x\left|x\right| = \begin{cases} x^2 &, x \ge 0 \\ -x^2 & x < 0 \end{cases}$
= area of region $OAB$ + area of region $OCD$ $= 2 \times$ Area of region $OAB$ $ = 2 \int\limits^{1}_{0} x^2 dx = \frac{2}{3}$ s units.