Addition Sums for Class 3

1) Anish’s Uncle Has Visited His Place. Anish Learned From Him to Solve a Sudoku Puzzle That He Has Given Him. Anish’s Uncle Has Given Him This Sudoku.

Solve the Sudoku. Then Check if the Sum of the Numbers in the Row and the Sum of the Numbers in the Columns Are the Same.

The solution to the sudoku is

In the row:

8 + 2 + 7 + 1 + 5 + 4 + 3 + 9 + 6 = 45
9 + 6 + 5 + 3 + 2 + 7 + 1 + 4 + 8 = 45
3 + 4 + 1 + 6 + 8 + 9 + 7 + 5 + 2 = 45

Adding the numbers for the other rows, we will get the same sum for all the rows because the numbers along every row are the same. So, the sum of the numbers in the rows will be the same.

In the column:

8 + 9 + 3 + 5 + 4 + 6 + 7 + 1 + 2 = 45
2 + 6 + 4 + 9 + 7 + 1 + 8 + 5 + 3 = 45

Adding the numbers for the other columns, we will get the same sum for all the columns because the numbers along every column are the same. So, the sum of the numbers in the column will be the same.

2) The Teacher Has Drawn Sudoku on the Board and Asked Each Student to Put a Number to Fill Up the Sudoku.

Solve the Sudoku. Then Check the Sum of Each 3 × 3 Grid Is the Same or Not.

Here is the solution to the sudoku that the students of the class have done.

Now, we have to check the sum of the numbers for each 3 × 3 grid.

Now in this blue marked 3 × 3 grid, the sum of the numbers is

7 + 9 + 3 + 6 + 5 + 4 + 1 + 2 + 8
= 16 + 3 + 6 + 5 + 4 + 1 + 2 + 8
= 19 + 6 + 5 + 4 + 1 + 10
= 25 + 10 + 10
= 35 + 10
= 45

Now in this pink marked 3 × 3 grid, the sum of the numbers is

2 + 1 + 9 + 3 + 4 + 6 + 7 + 5 + 8
= 2 + 10 + 7 + 6 + 12 + 8
= 12 + 7 + 6 + 20
= 32 + 13
= 45

Similarly, we can check for the other grids also. It is evident that the sum will be the same for all the 3 × 3 grids because the numbers in all the 3 × 3 grids are the same. Hence, the sum of all the 3 × 3 grids will be the same.