487 * 8 + 45270 : 3 : 10 = 3896 + 15090 : 10 = 3896 + 1509 = 5405
1) $\begin{array}{r}\times \underset{¯}{\begin{array}{r}487\\ 8\end{array}}\\ 3896\end{array}$;
2) $\begin{array}{cc}\begin{array}{l}\underset{¯}{\phantom{0}}45270\\ \phantom{0}\underset{¯}{3}\\ \underset{¯}{\phantom{0}}15\\ \phantom{0}\underset{¯}{15}\\ \phantom{00}\underset{¯}{\phantom{0}}2\\ \phantom{000}\underset{¯}{0}\\ \phantom{00}\underset{¯}{\phantom{0}}27\\ \phantom{000}\underset{¯}{27}\\ \phantom{0000}\underset{¯}{\phantom{0}}0\\ \phantom{00000}\underset{¯}{0}\\ \phantom{00000}0\end{array}& \begin{array}{l}\overline{)3}\\ \overline{\overline{)15090}}\end{array}\end{array}$;
3) 15090 : 10 = 1509;
4) $\begin{array}{r}\begin{array}{r}+\end{array}\underline{\begin{array}{r}3896\\ 1509\end{array}}\\ \begin{array}{r}5405\end{array}\end{array}$.
 
560 : 7 + (3820 − 850) = 80 + (3820 − 850) = 80 + 2970 = 3050
1) $\begin{array}{r}\begin{array}{r}-\end{array}\underline{\begin{array}{r}3820\\ 850\end{array}}\\ \begin{array}{r}2970\end{array}\end{array}$;
2) 560 : 7 = 80;
3) 80 + 2970 = 3050.