有理数的简算

$11.35 \times\left(-\frac{2}{3}\right)^{2}+2.1 \times\left(-\frac{2}{9}\right)-7.7 \times\left(\frac{-4}{3^{2}}\right)$

$\begin{aligned} & 11.35 \times \frac{4}{9}+2.1 \times\left(-\frac{2}{9}\right)-7.7 \times\left(-\frac{4}{9}\right) \\=& 11.35 \times \frac{4}{9}-2.1 \times \frac{2}{9}+7.7 \times \frac{4}{9} \\=& 11.35 \times 2 \times \frac{2}{9}-2.1 \times \frac{2}{9}+7.7 \times 2 \times \frac{2}{9} \\=& 22.7 \times \frac{2}{9}-2.1 \times \frac{2}{9}+15.4 \times \frac{2}{9} \\=&(22.7-2.1+15.4) \times \frac{2}{9} \\=& 36 \times \frac{2}{9} \\=& 8 \end{aligned}$