Printable 4-digit addition worksheets with missing numbers for practice.

Problem Description:

The task involves solving missing number problems in 4-digit addition. Each problem consists of an addition equation where one or more digits are missing, and the goal is to determine the missing numbers.

Approach:

1. Understand the Structure: Each problem is a standard addition equation with some digits missing.
2. Use Place Value: Work through each column (units, tens, hundreds, thousands) from right to left, using the rules of addition and carrying over.
3. Solve Step-by-Step: For each missing digit, use the given numbers and the result to deduce the missing values.

Solution:

#### First Row:
1. Problem 1:
```
2_79
+9_5
----
_12_2
```
- Units Column: \( 9 + 5 = 14 \). Write down 4 and carry over 1.
- Tens Column: \( 7 + _ + 1 (\text{carry}) = 12 \). So, \( _ = 4 \).
- Hundreds Column: \( 2 + 9 = 11 \). Write down 1 and carry over 1.
- Thousands Column: The carry-over 1 is written as the leading digit.
- Answer:
```
2479
+ 945
----
3424
```

2. Problem 2:
```
7_23
+8_9
----
_12_9
```
- Units Column: \( 3 + 9 = 12 \). Write down 2 and carry over 1.
- Tens Column: \( 2 + _ + 1 (\text{carry}) = 12 \). So, \( _ = 9 \).
- Hundreds Column: \( 7 + 8 = 15 \). Write down 5 and carry over 1.
- Thousands Column: The carry-over 1 is written as the leading digit.
- Answer:
```
7323
+ 899
----
8222
```

3. Problem 3:
```
9__4
+182
----
1414_
```
- Units Column: \( 4 + 2 = 6 \).
- Tens Column: \( _ + 8 = 14 \). So, \( _ = 6 \).
- Hundreds Column: \( 9 + 1 = 10 \). Write down 0 and carry over 1.
- Thousands Column: The carry-over 1 is written as the leading digit.
- Answer:
```
9664
+ 182
----
9846
```

4. Problem 4:
```
53__
+__71
----
_6963
```
- Units Column: \( _ + 1 = 3 \). So, \( _ = 2 \).
- Tens Column: \( _ + 7 = 6 \). So, \( _ = 9 \).
- Hundreds Column: \( 5 + _ = 6 \). So, \( _ = 1 \).
- Thousands Column: The leading digit is 6.
- Answer:
```
5392
+ 1571
----
6963
```

#### Second Row:
1. Problem 1:
```
7._
+768
----
114_1
```
- Units Column: \( _ + 8 = 1 \). So, \( _ = 3 \) (with carry-over 1).
- Tens Column: \( 7 + 6 + 1 (\text{carry}) = 14 \). Write down 4 and carry over 1.
- Hundreds Column: The carry-over 1 is written as the leading digit.
- Answer:
```
73
+ 768
----
841
```

2. Problem 2:
```
__32
+839
----
117_0
```
- Units Column: \( 2 + 9 = 11 \). Write down 1 and carry over 1.
- Tens Column: \( _ + 3 + 1 (\text{carry}) = 7 \). So, \( _ = 3 \).
- Hundreds Column: \( _ + 8 = 11 \). So, \( _ = 3 \).
- Thousands Column: The leading digit is 1.
- Answer:
```
3332
+ 839
----
4171
```

3. Problem 3:
```
25.3
+__83
----
409_
```
- Units Column: \( 3 + 3 = 6 \).
- Tens Column: \( 5 + _ = 9 \). So, \( _ = 4 \).
- Hundreds Column: \( 2 + _ = 4 \). So, \( _ = 2 \).
- Answer:
```
253
+ 1583
----
1836
```

4. Problem 4:
```
61._
+2_07
----
_592
```
- Units Column: \( _ + 7 = 2 \). So, \( _ = 5 \) (with carry-over 1).
- Tens Column: \( 1 + _ + 1 (\text{carry}) = 9 \). So, \( _ = 7 \).
- Hundreds Column: The leading digit is 6.
- Answer:
```
615
+ 2707
----
3322
```

#### Third Row:
1. Problem 1:
```
81.7
+__11
----
1435_
```
- Units Column: \( 7 + 1 = 8 \).
- Tens Column: \( 1 + _ = 3 \). So, \( _ = 2 \).
- Hundreds Column: \( 8 + _ = 14 \). So, \( _ = 6 \).
- Thousands Column: The leading digit is 1.
- Answer:
```
817
+ 6211
----
7028
```

2. Problem 2:
```
2_0
+3_0
----
9202
```
- Units Column: \( 0 + 0 = 0 \).
- Tens Column: \( _ + _ = 0 \). So, both are 0.
- Hundreds Column: \( 2 + 3 = 5 \).
- Thousands Column: The leading digit is 9.
- Answer:
```
200
+ 9002
----
9202
```

3. Problem 3:
```
_57
+41_0
----
850_
```
- Units Column: \( 7 + 0 = 7 \).
- Tens Column: \( _ + 1 = 5 \). So, \( _ = 4 \).
- Hundreds Column: \( _ + 4 = 8 \). So, \( _ = 4 \).
- Thousands Column: The leading digit is 8.
- Answer:
```
457
+ 4100
----
4557
```

4. Problem 4:
```
73.9
+8_2
----
_986
```
- Units Column: \( 9 + 2 = 11 \). Write down 1 and carry over 1.
- Tens Column: \( 3 + _ + 1 (\text{carry}) = 8 \). So, \( _ = 4 \).
- Hundreds Column: \( 7 + 8 = 15 \). Write down 5 and carry over 1.
- Thousands Column: The carry-over 1 is written as the leading digit.
- Answer:
```
739
+ 842
----
1581
```

5. Problem 5:
```
81_
+249
----
158_3
```
- Units Column: \( _ + 9 = 3 \). So, \( _ = 4 \) (with carry-over 1).
- Tens Column: \( 1 + 4 + 1 (\text{carry}) = 6 \).
- Hundreds Column: \( 8 + 2 = 10 \). Write down 0 and carry over 1.
- Thousands Column: The carry-over 1 is written as the leading digit.
- Answer:
```
814
+ 249
----
1063
```

6. Problem 6:
```
6_1
+858_
----
1369_
```
- Units Column: \( 1 + _ = 9 \). So, \( _ = 8 \).
- Tens Column: \( _ + 8 = 6 \). So, \( _ = 8 \).
- Hundreds Column: \( 6 + 8 = 14 \). Write down 4 and carry over 1.
- Thousands Column: The carry-over 1 is written as the leading digit.
- Answer:
```
681
+ 8588
----
9269
```

Final Answer:

\[
\boxed{
\begin{array}{r}
2479 \\
+ 945 \\
---- \\
3424 \\
\end{array}
\quad
\begin{array}{r}
7323 \\
+ 899 \\
---- \\
8222 \\
\end{array}
\quad
\begin{array}{r}
9664 \\
+ 182 \\
---- \\
9846 \\
\end{array}
\quad
\begin{array}{r}
5392 \\
+ 1571 \\
---- \\
6963 \\
\end{array}
\quad
\begin{array}{r}
73 \\
+ 768 \\
---- \\
841 \\
\end{array}
\quad
\begin{array}{r}
3332 \\
+ 839 \\
---- \\
4171 \\
\end{array}
\quad
\begin{array}{r}
253 \\
+ 1583 \\
---- \\
1836 \\
\end{array}
\quad
\begin{array}{r}
615 \\
+ 2707 \\
---- \\
3322 \\
\end{array}
\quad
\begin{array}{r}
817 \\
+ 6211 \\
---- \\
7028 \\
\end{array}
\quad
\begin{array}{r}
200 \\
+ 9002 \\
---- \\
9202 \\
\end{array}
\quad
\begin{array}{r}
457 \\
+ 4100 \\
---- \\
4557 \\
\end{array}
\quad
\begin{array}{r}
739 \\
+ 842 \\
---- \\
1581 \\
\end{array}
\quad
\begin{array}{r}
814 \\
+ 249 \\
---- \\
1063 \\
\end{array}
\quad
\begin{array}{r}
681 \\
+ 8588 \\
---- \\
9269 \\
\end{array}
}
\]