Vertical Subtraction: 2-digit and 2-digit numbers- regrouping of tens

$\begin{aligned} &83 \\ -& \\ &66 \\ &\underline{\phantom{776}} & \\ \end{aligned}$

17

$\begin{aligned} &47 \\ -& \\ &29 \\ &\underline{\phantom{776}} & \\ \end{aligned}$

18

$\begin{aligned} &98 \\ -& \\ &79 \\ &\underline{\phantom{776}} & \\ \end{aligned}$

19

$\begin{aligned} &53 \\ -& \\ &36\\ &\underline{\phantom{776}} & \\ \end{aligned}$

17

$\begin{aligned} &33 \\ -& \\ &15 \\ &\underline{\phantom{776}} & \\ \end{aligned}$

18

$\begin{aligned} &67 \\ -& \\ &48 \\ &\underline{\phantom{776}} & \\ \end{aligned}$

19

$\begin{aligned} &76 \\ -& \\ &57 \\ &\underline{\phantom{776}} & \\ \end{aligned}$

19

$\begin{aligned} &97 \\ -& \\ &68 \\ &\underline{\phantom{776}} & \\ \end{aligned}$

29

$\begin{aligned} &74 \\ -& \\ &38 \\ &\underline{\phantom{776}} & \\ \end{aligned}$

36

$\begin{aligned} &62 \\ -& \\ &37 \\ &\underline{\phantom{776}} & \\ \end{aligned}$

25