Đặt tính rồi tính: a) 345,6 - 27,92 b) 35,6 + 5,67 + 7,89 c) 56,78 x 7,8

* Hướng dẫn giải

a)

$\begin{array}{l}\underset{¯}{\begin{array}{l}345,6\\ -\\ 27,92\end{array}}\\ 317,68\end{array}$

b) 

$\begin{array}{l}\underset{¯}{\begin{array}{l}35,6\\ -\\ 5,67\\ +\\ 7,89\end{array}}\\ 37,82\end{array}$

c)

$\begin{array}{l}\underset{¯}{\begin{array}{l}\underset{¯}{\begin{array}{l}56,78\\ \times \\ 7,8\end{array}}\\ 45424\\ 39746\end{array}}\\ 442,884\end{array}$

d)