Tính bằng cách nhanh nhất: a. 13/50 + 0,09 + 41/100 +0,24

* Hướng dẫn giải

a. 

$$\begin{gathered} \frac{13}{50}+0,09 +\frac{41}{100}+0,24 \\ =\frac{26}{100}+\frac{9}{100}+\frac{41}{100}+\frac{24}{100} \\ =\left(\frac{26}{100}+\frac{24}{100}\right)+\left(\frac{9}{100}+\frac{41}{100}\right) \\ =10+7+8+9 \\ =34 \end{gathered}$$

b.

$$\begin{gathered} 9\frac{1}{4}+6\frac{2}{7}+7\frac{3}{5}+8\frac{2}{3}+\frac{2}{5}+\frac{1}{3}+\frac{5}{7}+\frac{3}{4} \\ =\frac{37}{4}+\frac{44}{7}+\frac{38}{5}+\frac{2}{5}+\frac{1}{3}+\frac{5}{7}+\frac{3}{4} \\ =\frac{1}{2}+\frac{1}{2} \\ =1 \end{gathered}$$