This is an addition problem because we want to know how many total sutents are in the after school programs when we put the two programs together. When we put things together we are adding. 

We can start at \(\displaystyle 7\) and count up \(\displaystyle 11\).

\(\displaystyle 7,8,9,10,11,12,13,14,15,16,17,18\)

\(\displaystyle \frac{\begin{array}[b]{r}7\\ +\ 11\end{array}}{ \ \ \ \space 18}\)

This is an addition problem because we want to know how many total chapter he has to read when we put the English and the science chapters together. When we put things together we are adding. 

We can start at \(\displaystyle 2\) and count up \(\displaystyle 4\).

\(\displaystyle 2,3,4,5,6\)

\(\displaystyle \frac{\begin{array}[b]{r}2\\ +\ 4\end{array}}{ \ \ \ \space 6}\)

This is an addition problem because we want to know how many total students there are when we put the boys and the girls together. When we put things together we are adding. 

We can start at \(\displaystyle 8\) and count up \(\displaystyle 8\).

\(\displaystyle 8,9,10,11,12,13,14,15,16\)

\(\displaystyle \frac{\begin{array}[b]{r}8\\ +\ 8\end{array}}{ \ \ \space 16}\)

This is an addition problem because we want to know how many total parts there are when we put the singing and the talking parts together. When we put things together we are adding. 

We can start at \(\displaystyle 8\) and count up \(\displaystyle 3\).

\(\displaystyle 8,9,10,11\)

\(\displaystyle \frac{\begin{array}[b]{r}8\\ +\ 3\end{array}}{ \ \ \space 11}\)

This is an addition problem because we want to know how many total slices of pizza we have when we put the medium pizza slices together with the large pizza slices. When we put things together we are adding. 

We can start at \(\displaystyle 12\) and count up \(\displaystyle 8\).

\(\displaystyle 12,13,14,15,16,17,18,19,20\)

\(\displaystyle \frac{\begin{array}[b]{r}12\\ +\ 8\end{array}}{ \ \ \space 20}\)

This is an addition problem because we are putting the frogs in the two tanks together. When we put things together we are adding. 

We can start at \(\displaystyle 5\) and count up \(\displaystyle 6\).

\(\displaystyle 5,6,7,8,9,10,11\)

\(\displaystyle \frac{\begin{array}[b]{r}5\\ +\ 6\end{array}}{ \ \ \space 11}\)

This is a subtraction problem because the tree lost branches, so it will have less than what it started with. 

We can start at \(\displaystyle 13\) and count back \(\displaystyle 7.\)

\(\displaystyle 13,12,11,10,9,8,7,6\)

\(\displaystyle \frac{\begin{array}[b]{r}13\\ -\ 7\end{array}}{ \ \ \ \space 6}\)

This is a subtraction problem because Megan is giving some of her markers away, so she will have less than what she started with. 

We can start at \(\displaystyle 12\) and count back \(\displaystyle 6\).

\(\displaystyle 12,11,10,9,8,7,6\)

\(\displaystyle \frac{\begin{array}[b]{r}12\\ -\ 6\end{array}}{ \ \ \ \space 6}\)

This is a subtraction problem because we are finding the difference in weight between the truck and the panda. 

We can start at \(\displaystyle 19\) and count back \(\displaystyle 7\).

\(\displaystyle 19,18,17,16,15,14,13,12\)

\(\displaystyle \frac{\begin{array}[b]{r}19\\ -\ 7\end{array}}{ \ \ \space 12}\)

This is a subtraction problem because Jess has worn some of her shirts, so her total number of shirts in the drawer is decreasing.

We can start at \(\displaystyle 18\) and count back \(\displaystyle 7\).

\(\displaystyle 18,17,16,15,14,13,12,11\) 

\(\displaystyle \frac{\begin{array}[b]{r}18\\ -\ 7\end{array}}{ \ \ \ \space11}\)