3-Digit Addition Worksheets -Worksheets Library - Free Printable

The image shows two sets of 3-digit addition problems: one without regrouping and one with regrouping. Below, I will solve the problems step by step.

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Left Worksheet: 3-Digit Addition Without Regrouping

#### Problem 1:
\[
\begin{array}{r}
235 \\
+324 \\
\hline
\end{array}
\]
- Add the ones place: \(5 + 4 = 9\)
- Add the tens place: \(3 + 2 = 5\)
- Add the hundreds place: \(2 + 3 = 5\)

\[
\boxed{559}
\]

#### Problem 2:
\[
\begin{array}{r}
347 \\
+232 \\
\hline
\end{array}
\]
- Add the ones place: \(7 + 2 = 9\)
- Add the tens place: \(4 + 3 = 7\)
- Add the hundreds place: \(3 + 2 = 5\)

\[
\boxed{579}
\]

#### Problem 3:
\[
\begin{array}{r}
671 \\
+328 \\
\hline
\end{array}
\]
- Add the ones place: \(1 + 8 = 9\)
- Add the tens place: \(7 + 2 = 9\)
- Add the hundreds place: \(6 + 3 = 9\)

\[
\boxed{999}
\]

#### Problem 4:
\[
\begin{array}{r}
754 \\
+325 \\
\hline
\end{array}
\]
- Add the ones place: \(4 + 5 = 9\)
- Add the tens place: \(5 + 2 = 7\)
- Add the hundreds place: \(7 + 3 = 10\) (write 0, carry 1)

\[
\boxed{1079}
\]

#### Problem 5:
\[
\begin{array}{r}
644 \\
+235 \\
\hline
\end{array}
\]
- Add the ones place: \(4 + 5 = 9\)
- Add the tens place: \(4 + 3 = 7\)
- Add the hundreds place: \(6 + 2 = 8\)

\[
\boxed{879}
\]

#### Problem 6:
\[
\begin{array}{r}
532 \\
+346 \\
\hline
\end{array}
\]
- Add the ones place: \(2 + 6 = 8\)
- Add the tens place: \(3 + 4 = 7\)
- Add the hundreds place: \(5 + 3 = 8\)

\[
\boxed{878}
\]

#### Problem 7:
\[
\begin{array}{r}
423 \\
+546 \\
\hline
\end{array}
\]
- Add the ones place: \(3 + 6 = 9\)
- Add the tens place: \(2 + 4 = 6\)
- Add the hundreds place: \(4 + 5 = 9\)

\[
\boxed{969}
\]

#### Problem 8:
\[
\begin{array}{r}
324 \\
+523 \\
\hline
\end{array}
\]
- Add the ones place: \(4 + 3 = 7\)
- Add the tens place: \(2 + 2 = 4\)
- Add the hundreds place: \(3 + 5 = 8\)

\[
\boxed{847}
\]

#### Problem 9:
\[
\begin{array}{r}
351 \\
+246 \\
\hline
\end{array}
\]
- Add the ones place: \(1 + 6 = 7\)
- Add the tens place: \(5 + 4 = 9\)
- Add the hundreds place: \(3 + 2 = 5\)

\[
\boxed{597}
\]

#### Problem 10:
\[
\begin{array}{r}
615 \\
+243 \\
\hline
\end{array}
\]
- Add the ones place: \(5 + 3 = 8\)
- Add the tens place: \(1 + 4 = 5\)
- Add the hundreds place: \(6 + 2 = 8\)

\[
\boxed{858}
\]

#### Problem 11:
\[
\begin{array}{r}
532 \\
+134 \\
\hline
\end{array}
\]
- Add the ones place: \(2 + 4 = 6\)
- Add the tens place: \(3 + 3 = 6\)
- Add the hundreds place: \(5 + 1 = 6\)

\[
\boxed{666}
\]

#### Problem 12:
\[
\begin{array}{r}
324 \\
+252 \\
\hline
\end{array}
\]
- Add the ones place: \(4 + 2 = 6\)
- Add the tens place: \(2 + 5 = 7\)
- Add the hundreds place: \(3 + 2 = 5\)

\[
\boxed{576}
\]

---

Right Worksheet: 3-Digit Addition With Regrouping

#### Problem 1:
\[
\begin{array}{r}
432 \\
+765 \\
\hline
\end{array}
\]
- Add the ones place: \(2 + 5 = 7\)
- Add the tens place: \(3 + 6 = 9\)
- Add the hundreds place: \(4 + 7 = 11\) (write 1, carry 1)

\[
\boxed{1197}
\]

#### Problem 2:
\[
\begin{array}{r}
743 \\
+538 \\
\hline
\end{array}
\]
- Add the ones place: \(3 + 8 = 11\) (write 1, carry 1)
- Add the tens place: \(4 + 3 + 1 = 8\)
- Add the hundreds place: \(7 + 5 = 12\) (write 2, carry 1)

\[
\boxed{1281}
\]

#### Problem 3:
\[
\begin{array}{r}
634 \\
+462 \\
\hline
\end{array}
\]
- Add the ones place: \(4 + 2 = 6\)
- Add the tens place: \(3 + 6 = 9\)
- Add the hundreds place: \(6 + 4 = 10\) (write 0, carry 1)

\[
\boxed{1096}
\]

#### Problem 4:
\[
\begin{array}{r}
647 \\
+265 \\
\hline
\end{array}
\]
- Add the ones place: \(7 + 5 = 12\) (write 2, carry 1)
- Add the tens place: \(4 + 6 + 1 = 11\) (write 1, carry 1)
- Add the hundreds place: \(6 + 2 + 1 = 9\)

\[
\boxed{912}
\]

#### Problem 5:
\[
\begin{array}{r}
965 \\
+634 \\
\hline
\end{array}
\]
- Add the ones place: \(5 + 4 = 9\)
- Add the tens place: \(6 + 3 = 9\)
- Add the hundreds place: \(9 + 6 = 15\) (write 5, carry 1)

\[
\boxed{1599}
\]

#### Problem 6:
\[
\begin{array}{r}
854 \\
+568 \\
\hline
\end{array}
\]
- Add the ones place: \(4 + 8 = 12\) (write 2, carry 1)
- Add the tens place: \(5 + 6 + 1 = 12\) (write 2, carry 1)
- Add the hundreds place: \(8 + 5 + 1 = 14\) (write 4, carry 1)

\[
\boxed{1422}
\]

#### Problem 7:
\[
\begin{array}{r}
778 \\
+854 \\
\hline
\end{array}
\]
- Add the ones place: \(8 + 4 = 12\) (write 2, carry 1)
- Add the tens place: \(7 + 5 + 1 = 13\) (write 3, carry 1)
- Add the hundreds place: \(7 + 8 + 1 = 16\) (write 6, carry 1)

\[
\boxed{1632}
\]

#### Problem 8:
\[
\begin{array}{r}
468 \\
+576 \\
\hline
\end{array}
\]
- Add the ones place: \(8 + 6 = 14\) (write 4, carry 1)
- Add the tens place: \(6 + 7 + 1 = 14\) (write 4, carry 1)
- Add the hundreds place: \(4 + 5 + 1 = 10\) (write 0, carry 1)

\[
\boxed{1044}
\]

#### Problem 9:
\[
\begin{array}{r}
366 \\
+854 \\
\hline
\end{array}
\]
- Add the ones place: \(6 + 4 = 10\) (write 0, carry 1)
- Add the tens place: \(6 + 5 + 1 = 12\) (write 2, carry 1)
- Add the hundreds place: \(3 + 8 + 1 = 12\) (write 2, carry 1)

\[
\boxed{1220}
\]

#### Problem 10:
\[
\begin{array}{r}
834 \\
+365 \\
\hline
\end{array}
\]
- Add the ones place: \(4 + 5 = 9\)
- Add the tens place: \(3 + 6 = 9\)
- Add the hundreds place: \(8 + 3 = 11\) (write 1, carry 1)

\[
\boxed{1199}
\]

#### Problem 11:
\[
\begin{array}{r}
472 \\
+645 \\
\hline
\end{array}
\]
- Add the ones place: \(2 + 5 = 7\)
- Add the tens place: \(7 + 4 = 11\) (write 1, carry 1)
- Add the hundreds place: \(4 + 6 + 1 = 11\) (write 1, carry 1)

\[
\boxed{1117}
\]

#### Problem 12:
\[
\begin{array}{r}
585 \\
+378 \\
\hline
\end{array}
\]
- Add the ones place: \(5 + 8 = 13\) (write 3, carry 1)
- Add the tens place: \(8 + 7 + 1 = 16\) (write 6, carry 1)
- Add the hundreds place: \(5 + 3 + 1 = 9\)

\[
\boxed{963}
\]

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Final Answers:

- Without Regrouping: \(\boxed{559, 579, 999, 1079, 879, 878, 969, 847, 597, 858, 666, 576}\)
- With Regrouping: \(\boxed{1197, 1281, 1096, 912, 1599, 1422, 1632, 1044, 1220, 1199, 1117, 963}\)