Math worksheet for practicing two-digit addition problems.

To solve the problem, we need to add the numbers in each pair and write down the correct answers. Let's go through each addition step by step.

Problem 1:

$$
\begin{array}{r}
51 \\
+42 \\
\hline
\end{array}
$$
- Add the ones place: \(1 + 2 = 3\)
- Add the tens place: \(5 + 4 = 9\)
- Result: \(93\)

Problem 2:

$$
\begin{array}{r}
37 \\
+42 \\
\hline
\end{array}
$$
- Add the ones place: \(7 + 2 = 9\)
- Add the tens place: \(3 + 4 = 7\)
- Result: \(79\)

Problem 3:

$$
\begin{array}{r}
42 \\
+36 \\
\hline
\end{array}
$$
- Add the ones place: \(2 + 6 = 8\)
- Add the tens place: \(4 + 3 = 7\)
- Result: \(78\)

Problem 4:

$$
\begin{array}{r}
52 \\
+34 \\
\hline
\end{array}
$$
- Add the ones place: \(2 + 4 = 6\)
- Add the tens place: \(5 + 3 = 8\)
- Result: \(86\)

Problem 5:

$$
\begin{array}{r}
33 \\
+35 \\
\hline
\end{array}
$$
- Add the ones place: \(3 + 5 = 8\)
- Add the tens place: \(3 + 3 = 6\)
- Result: \(68\)

Problem 6:

$$
\begin{array}{r}
27 \\
+62 \\
\hline
\end{array}
$$
- Add the ones place: \(7 + 2 = 9\)
- Add the tens place: \(2 + 6 = 8\)
- Result: \(89\)

Problem 7:

$$
\begin{array}{r}
11 \\
+34 \\
\hline
\end{array}
$$
- Add the ones place: \(1 + 4 = 5\)
- Add the tens place: \(1 + 3 = 4\)
- Result: \(45\)

Problem 8:

$$
\begin{array}{r}
67 \\
+12 \\
\hline
\end{array}
$$
- Add the ones place: \(7 + 2 = 9\)
- Add the tens place: \(6 + 1 = 7\)
- Result: \(79\)

Problem 9:

$$
\begin{array}{r}
34 \\
+42 \\
\hline
\end{array}
$$
- Add the ones place: \(4 + 2 = 6\)
- Add the tens place: \(3 + 4 = 7\)
- Result: \(76\)

Problem 10:

$$
\begin{array}{r}
23 \\
+45 \\
\hline
\end{array}
$$
- Add the ones place: \(3 + 5 = 8\)
- Add the tens place: \(2 + 4 = 6\)
- Result: \(68\)

Problem 11:

$$
\begin{array}{r}
34 \\
+25 \\
\hline
\end{array}
$$
- Add the ones place: \(4 + 5 = 9\)
- Add the tens place: \(3 + 2 = 5\)
- Result: \(59\)

Problem 12:

$$
\begin{array}{r}
42 \\
+31 \\
\hline
\end{array}
$$
- Add the ones place: \(2 + 1 = 3\)
- Add the tens place: \(4 + 3 = 7\)
- Result: \(73\)

Final Answers:

$$
\boxed{
\begin{array}{lll}
1) & 93 & 2) & 79 & 3) & 78 \\
4) & 86 & 5) & 68 & 6) & 89 \\
7) & 45 & 8) & 79 & 9) & 76 \\
10) & 68 & 11) & 59 & 12) & 73 \\
\end{array}
}
$$