Vertical Subtraction: Simple subtraction of double digits

$\begin{aligned} &89 \\ -& \\ &~~9 \\ &\underline{\phantom{776}} & \\ \end{aligned}$

80

$\begin{aligned} &15 \\ -& \\ &~~4 \\ &\underline{\phantom{776}} & \\ \end{aligned}$

11

$\begin{aligned} &27 \\ -& \\ &~~3 \\ &\underline{\phantom{776}} & \\ \end{aligned}$

24

$\begin{aligned} &48 \\ -& \\ &~~7 \\ &\underline{\phantom{776}} & \\ \end{aligned}$

41

$\begin{aligned} &56 \\ -& \\ &~~5 \\ &\underline{\phantom{776}} & \\ \end{aligned}$

51

$\begin{aligned} &39 \\ -& \\ &~~6 \\ &\underline{\phantom{776}} & \\ \end{aligned}$

33

$\begin{aligned} &64 \\ -& \\ &~~1 \\ &\underline{\phantom{776}} & \\ \end{aligned}$

63

$\begin{aligned} &73 \\ -& \\ &~~3 \\ &\underline{\phantom{776}} & \\ \end{aligned}$

70

$\begin{aligned} &98 \\ -& \\ &~~2 \\ &\underline{\phantom{776}} & \\ \end{aligned}$

96

$\begin{aligned} &99 \\ -& \\ &~~9 \\ &\underline{\phantom{776}} & \\ \end{aligned}$

90