Easy 150 Kids SUDOKU Puzzles With Solution, Printable Sudoku Sheets - Free Printable

Problem: Solve the 4x4 Sudoku puzzles provided in the image.

#### Rules for 4x4 Sudoku:
1. Each row must contain the numbers 1, 2, 3, and 4 exactly once.
2. Each column must contain the numbers 1, 2, 3, and 4 exactly once.
3. Each 2x2 subgrid (box) must contain the numbers 1, 2, 3, and 4 exactly once.

#### Puzzle #1:
```
| | | 3 | 1 |
|---|---|---|---|
| | 3 | | |
|---|---|---|---|
| 3 | | | 2 |
|---|---|---|---|
| 2 | | 4 | |
```

Solution:
1. Start with the given numbers and fill in the missing ones while adhering to the rules.
2. In the first row, we have `| _ | _ | 3 | 1 |`. The missing numbers are 2 and 4. Since the third column already has a 3, the first cell must be 2, and the second cell must be 4.
```
| 2 | 4 | 3 | 1 |
```
3. In the second row, we have `| _ | 3 | _ | _ |`. The missing numbers are 1, 2, and 4. Since the second column already has a 3, and the third column cannot have a 3 again, we place 1 in the third column and 2 in the fourth column. The first cell must be 4.
```
| 2 | 4 | 3 | 1 |
| 4 | 3 | 1 | 2 |
```
4. In the third row, we have `| 3 | _ | _ | 2 |`. The missing numbers are 1 and 4. Since the first column already has a 3, and the fourth column has a 2, we place 1 in the second column and 4 in the third column.
```
| 2 | 4 | 3 | 1 |
| 4 | 3 | 1 | 2 |
| 3 | 1 | 4 | 2 |
```
5. In the fourth row, we have `| 2 | _ | 4 | _ |`. The missing numbers are 1 and 3. Since the first column already has a 2, and the third column has a 4, we place 3 in the second column and 1 in the fourth column.
```
| 2 | 4 | 3 | 1 |
| 4 | 3 | 1 | 2 |
| 3 | 1 | 4 | 2 |
| 2 | 3 | 4 | 1 |
```

Final Solution for Puzzle #1:
```
| 2 | 4 | 3 | 1 |
| 4 | 3 | 1 | 2 |
| 3 | 1 | 4 | 2 |
| 2 | 3 | 4 | 1 |
```

---

#### Puzzle #2:
```
| 2 | 4 | _ | 1 |
|---|---|---|---|
| _ | 1 | _ | 2 |
|---|---|---|---|
| 1 | _ | _ | 2 |
|---|---|---|---|
| _ | _ | 1 | _ |
```

Solution:
1. Start with the given numbers and fill in the missing ones while adhering to the rules.
2. In the first row, we have `| 2 | 4 | _ | 1 |`. The missing numbers are 3 and 4. Since the first column already has a 2, and the fourth column has a 1, we place 3 in the third column.
```
| 2 | 4 | 3 | 1 |
```
3. In the second row, we have `| _ | 1 | _ | 2 |`. The missing numbers are 3 and 4. Since the second column already has a 1, and the fourth column has a 2, we place 4 in the first column and 3 in the third column.
```
| 2 | 4 | 3 | 1 |
| 4 | 1 | 3 | 2 |
```
4. In the third row, we have `| 1 | _ | _ | 2 |`. The missing numbers are 3 and 4. Since the first column already has a 1, and the fourth column has a 2, we place 4 in the second column and 3 in the third column.
```
| 2 | 4 | 3 | 1 |
| 4 | 1 | 3 | 2 |
| 1 | 4 | 3 | 2 |
```
5. In the fourth row, we have `| _ | _ | 1 | _ |`. The missing numbers are 2, 3, and 4. Since the third column already has a 1, and the first column cannot have a 2 or 4 (as they are already used in the first and second rows), we place 3 in the first column, 2 in the second column, and 4 in the fourth column.
```
| 2 | 4 | 3 | 1 |
| 4 | 1 | 3 | 2 |
| 1 | 4 | 3 | 2 |
| 3 | 2 | 1 | 4 |
```

Final Solution for Puzzle #2:
```
| 2 | 4 | 3 | 1 |
| 4 | 1 | 3 | 2 |
| 1 | 4 | 3 | 2 |
| 3 | 2 | 1 | 4 |
```

---

#### Puzzle #3:
```
| 3 | 1 | _ | _ |
|---|---|---|---|
| _ | 4 | 3 | _ |
|---|---|---|---|
| 1 | _ | _ | 4 |
|---|---|---|---|
| _ | _ | 1 | 3 |
```

Solution:
1. Start with the given numbers and fill in the missing ones while adhering to the rules.
2. In the first row, we have `| 3 | 1 | _ | _ |`. The missing numbers are 2 and 4. Since the first column already has a 3, and the second column has a 1, we place 2 in the third column and 4 in the fourth column.
```
| 3 | 1 | 2 | 4 |
```
3. In the second row, we have `| _ | 4 | 3 | _ |`. The missing numbers are 1 and 2. Since the second column already has a 4, and the third column has a 3, we place 1 in the first column and 2 in the fourth column.
```
| 3 | 1 | 2 | 4 |
| 1 | 4 | 3 | 2 |
```
4. In the third row, we have `| 1 | _ | _ | 4 |`. The missing numbers are 2 and 3. Since the first column already has a 1, and the fourth column has a 4, we place 2 in the second column and 3 in the third column.
```
| 3 | 1 | 2 | 4 |
| 1 | 4 | 3 | 2 |
| 1 | 2 | 3 | 4 |
```
5. In the fourth row, we have `| _ | _ | 1 | 3 |`. The missing numbers are 2 and 4. Since the third column already has a 1, and the fourth column has a 3, we place 4 in the first column and 2 in the second column.
```
| 3 | 1 | 2 | 4 |
| 1 | 4 | 3 | 2 |
| 1 | 2 | 3 | 4 |
| 4 | 2 | 1 | 3 |
```

Final Solution for Puzzle #3:
```
| 3 | 1 | 2 | 4 |
| 1 | 4 | 3 | 2 |
| 1 | 2 | 3 | 4 |
| 4 | 2 | 1 | 3 |
```

---

#### Puzzle #4:
```
| _ | _ | _ | 4 |
|---|---|---|---|
| _ | 4 | _ | _ |
|---|---|---|---|
| 2 | _ | _ | _ |
|---|---|---|---|
| _ | 1 | 2 | 3 |
```

Solution:
1. Start with the given numbers and fill in the missing ones while adhering to the rules.
2. In the fourth row, we have `| _ | 1 | 2 | 3 |`. The missing number is 4. Since the fourth column already has a 4, we place 4 in the first column.
```
| _ | _ | _ | 4 |
| _ | 4 | _ | _ |
| 2 | _ | _ | _ |
| 4 | 1 | 2 | 3 |
```
3. In the first row, we have `| _ | _ | _ | 4 |`. The missing numbers are 1, 2, and 3. Since the fourth column already has a 4, and the first column cannot have a 2 (as it is used in the third row), we place 1 in the first column, 2 in the second column, and 3 in the third column.
```
| 1 | 2 | 3 | 4 |
| _ | 4 | _ | _ |
| 2 | _ | _ | _ |
| 4 | 1 | 2 | 3 |
```
4. In the second row, we have `| _ | 4 | _ | _ |`. The missing numbers are 1, 2, and 3. Since the second column already has a 4, and the first column cannot have a 1 (as it is used in the first row), we place 3 in the first column, 1 in the third column, and 2 in the fourth column.
```
| 1 | 2 | 3 | 4 |
| 3 | 4 | 1 | 2 |
| 2 | _ | _ | _ |
| 4 | 1 | 2 | 3 |
```
5. In the third row, we have `| 2 | _ | _ | _ |`. The missing numbers are 1, 3, and 4. Since the first column already has a 2, and the fourth column cannot have a 4 (as it is used in the first row), we place 3 in the second column, 4 in the third column, and 1 in the fourth column.
```
| 1 | 2 | 3 | 4 |
| 3 | 4 | 1 | 2 |
| 2 | 3 | 4 | 1 |
| 4 | 1 | 2 | 3 |
```

Final Solution for Puzzle #4:
```
| 1 | 2 | 3 | 4 |
| 3 | 4 | 1 | 2 |
| 2 | 3 | 4 | 1 |
| 4 | 1 | 2 | 3 |
```

---

Final Answers:

1. Puzzle #1:
```
| 2 | 4 | 3 | 1 |
| 4 | 3 | 1 | 2 |
| 3 | 1 | 4 | 2 |
| 2 | 3 | 4 | 1 |
```
2. Puzzle #2:
```
| 2 | 4 | 3 | 1 |
| 4 | 1 | 3 | 2 |
| 1 | 4 | 3 | 2 |
| 3 | 2 | 1 | 4 |
```
3. Puzzle #3:
```
| 3 | 1 | 2 | 4 |
| 1 | 4 | 3 | 2 |
| 1 | 2 | 3 | 4 |
| 4 | 2 | 1 | 3 |
```
4. Puzzle #4:
```
| 1 | 2 | 3 | 4 |
| 3 | 4 | 1 | 2 |
| 2 | 3 | 4 | 1 |
| 4 | 1 | 2 | 3 |
```

Boxed Final Answer:
\[
\boxed{
\begin{array}{cccc}
\text{Puzzle #1:} & \begin{array}{|c|c|c|c|}
\hline
2 & 4 & 3 & 1 \\
\hline
4 & 3 & 1 & 2 \\
\hline
3 & 1 & 4 & 2 \\
\hline
2 & 3 & 4 & 1 \\
\hline
\end{array} &
\text{Puzzle #2:} & \begin{array}{|c|c|c|c|}
\hline
2 & 4 & 3 & 1 \\
\hline
4 & 1 & 3 & 2 \\
\hline
1 & 4 & 3 & 2 \\
\hline
3 & 2 & 1 & 4 \\
\hline
\end{array} \\
\text{Puzzle #3:} & \begin{array}{|c|c|c|c|}
\hline
3 & 1 & 2 & 4 \\
\hline
1 & 4 & 3 & 2 \\
\hline
1 & 2 & 3 & 4 \\
\hline
4 & 2 & 1 & 3 \\
\hline
\end{array} &
\text{Puzzle #4:} & \begin{array}{|c|c|c|c|}
\hline
1 & 2 & 3 & 4 \\
\hline
3 & 4 & 1 & 2 \\
\hline
2 & 3 & 4 & 1 \\
\hline
4 & 1 & 2 & 3 \\
\hline
\end{array}
\end{array}
}
\]