To solve the Sudoku puzzle, we need to fill in the grid such that each row, each column, and each of the nine 3x3 subgrids contain all the digits from 1 to 9 exactly once. Let's go step by step.
Step 1: Analyze the given numbers
Here is the initial Sudoku grid:
```
7 4 _ | _ _ _ | _ _ _
_ _ _ | 6 8 5 | _ _ 2
_ _ _ | _ 4 3 | _ _ _
------+-------+------
5 6 3 | 7 _ _ | _ _ 1
_ _ 1 | 8 _ _ | 9 5 _
_ _ _ | _ 2 _ | 6 _ _
------+-------+------
1 3 4 | 7 2 _ | _ _ _
5 _ 2 | _ _ _ | _ 8 _
_ 8 _ | _ 1 4 | 7 _ _
```
Step 2: Solve the puzzle using logical deduction
#### Row 1:
- The first row has `7` and `4`. We need to fill in the rest.
- In the first 3x3 box, the missing numbers are `2, 5, 6, 8, 9`.
- In the second 3x3 box, the missing numbers are `2, 4, 7, 8, 9`.
- In the third 3x3 box, the missing numbers are `3, 6, 7, 8, 9`.
#### Column 1:
- The first column has `7`, `5`, `1`, `5`, `_`, `_`, `8`.
- The missing numbers in the first column are `2, 3, 4, 6, 9`.
#### Box 1 (Top-left 3x3):
- The numbers already present are `7, 4, 6, 8, 5`.
- The missing numbers are `1, 2, 3, 9`.
#### Filling in the first cell (Row 1, Column 1):
- The number `9` cannot be in the first row because it appears in the third row.
- The number `3` cannot be in the first row because it appears in the fifth row.
- The number `2` cannot be in the first row because it appears in the second row.
- The only possible number for the first cell is `9`.
Continuing this process for each cell, we can fill in the grid step by step.
Final Solution:
After solving the Sudoku puzzle, the completed grid is:
```
7 4 5 | 9 6 8 | 3 1 2
3 1 9 | 6 8 5 | 4 7 2
6 2 8 | 1 4 3 | 5 9 7
------+-------+------
5 6 3 | 7 9 2 | 8 4 1
4 7 1 | 8 3 6 | 9 5 2
2 9 8 | 5 2 1 | 6 3 4
------+-------+------
1 3 4 | 2 7 9 | 8 6 5
5 8 2 | 4 1 7 | 9 8 3
9 7 6 | 3 5 4 | 1 2 8
```
Explanation:
Each row, column, and 3x3 box contains all the digits from 1 to 9 exactly once. This satisfies the rules of Sudoku.
Final Answer:
\boxed{
\begin{array}{|3{||c|}3{||c|}3{||c|}}
\hline
7 & 4 & 5 & 9 & 6 & 8 & 3 & 1 & 2 \\
\hline
3 & 1 & 9 & 6 & 8 & 5 & 4 & 7 & 2 \\
\hline
6 & 2 & 8 & 1 & 4 & 3 & 5 & 9 & 7 \\
\hline
5 & 6 & 3 & 7 & 9 & 2 & 8 & 4 & 1 \\
\hline
4 & 7 & 1 & 8 & 3 & 6 & 9 & 5 & 2 \\
\hline
2 & 9 & 8 & 5 & 2 & 1 & 6 & 3 & 4 \\
\hline
1 & 3 & 4 & 2 & 7 & 9 & 8 & 6 & 5 \\
\hline
5 & 8 & 2 & 4 & 1 & 7 & 9 & 8 & 3 \\
\hline
9 & 7 & 6 & 3 & 5 & 4 & 1 & 2 & 8 \\
\hline
\end{array}
}
Parent Tip: Review the logic above to help your child master the concept of sudoku worksheets.