Tính bằng cách thuận tiện. (125 x 0,67) x 8 8/9 x 7/11 +4/11 x 8/9

= 1 000 x 0,67

                  = 670

\(\frac{8}{9} \times \frac{7}{{11}} + \frac{4}{{11}} \times \frac{8}{9}\)

= \(\frac{8}{9} \times \left( {\frac{7}{{11}} + \frac{4}{{11}}} \right)\)

                   =\(\frac{8}{9} \times 1\)

                   =\(\frac{8}{9}\)