3.

3. 85 - 32 = 53（箱）

4.列竖式计算。
58−27= 45−13= 86−34= 97−55=
45−26= 90−69= 63−8= 32−18=

4. 58 - 27 = 31
$\begin{array}{r} \mathrm{十}\quad\mathrm{个}\\ \mathrm{位}\quad\mathrm{位}\\ 5\ 8\\ -2\ 7\\ \hline 3\ 1\end{array}$
45 - 13 = 32
$\begin{array}{r} \mathrm{十}\quad\mathrm{个}\\ \mathrm{位}\quad\mathrm{位}\\ 4\ 5\\ -1\ 3\\ \hline 3\ 2\end{array}$
86 - 34 = 52
$\begin{array}{r} \mathrm{十}\quad\mathrm{个}\\ \mathrm{位}\quad\mathrm{位}\\ 8\ 6\\ -3\ 4\\ \hline 5\ 2\end{array}$
97 - 55 = 42
$\begin{array}{r} \mathrm{十}\quad\mathrm{个}\\ \mathrm{位}\quad\mathrm{位}\\ 9\ 7\\ -5\ 5\\ \hline 4\ 2\end{array}$
45 - 26 = 19
$\begin{array}{r} \mathrm{十}\quad\mathrm{个}\\ \mathrm{位}\quad\mathrm{位}\\ \dot{4}\ 5\\ -2\ 6\\ \hline 1\ 9\end{array}$
90 - 69 = 21
$\begin{array}{r} \mathrm{十}\quad\mathrm{个}\\ \mathrm{位}\quad\mathrm{位}\\ \dot{9}\ 0\\ -6\ 9\\ \hline 2\ 1\end{array}$

63 - 8 = 55
$\begin{array}{r} \mathrm{十}\quad\mathrm{个}\\ \mathrm{位}\quad\mathrm{位}\\ \dot{6}\ 3\\ -\ \ \ 8\\ \hline 5\ 5\end{array}$

32 - 18 = 14
$\begin{array}{r} \mathrm{十}\quad\mathrm{个}\\ \mathrm{位}\quad\mathrm{位}\\ \dot{3}\ 2\\ -1\ 8\\ \hline 1\ 4\end{array}$

5.叶子盖住的是几?

5.