The idea for this puzzle came from when I was trying to create a new form of Sudoku. As I was playing around with the numbers, I found out that the largest 5 number combination is 5+6+7+8+9 = 35 (obviously) and that the remaining number (1,2,3,4) can be used to form a 5. Based on this, I created a 7x7 grid Sudoku/Kakuro inspired puzzle game. Hence, 40 Sum was born.

The rules are pretty simple actually, especially if you're familiar with both games:

- The objective of the game is to fill a 7x7 grid with numbers between 1-9 (Since there are only 7 columns and 7 rows, you can skip 2 numbers on each)

- Similar to Sudoku, each number must NOT be repeated in the same column, the same row, or any 1 cell around it.

- The sum of all the numbers in each row/column must be equal to 40.

Here is a sample of a completed puzzle:

Before:

5 - - 1 - - -

- 2 - 9 6 8 7

9 6 8 7 2 5 3

8 - 3 - - - -

6 9 2 - - - -

2 - - - 5 9 8

7 5 9 - 8 1 -

Solved:

5 8 6 1 7 4 9 - 40

3 2 5 9 6 8 7 - 40

9 6 8 7 2 5 3 - 40

8 7 3 5 9 6 2 - 40

6 9 2 8 3 7 5 - 40

2 3 7 6 5 9 8 - 40

7 5 9 4 8 1 6- 40

| | | | | | |

40404040404040

For you wondering on how to solve the puzzle, here are the steps (don't open it if you want to figure it out yourself):

**Hidden Text:**Show

Sorry is my English is not so good btw, it's not my primary language.

Here's a couple more of the puzzles to try out, see I you can figure out the answer! I'll be posting the solution next week.

- Code: Select all
`Puzzle #1`

8 7 1 5 9 - -

- - - 7 8 1 -

7 - 5 - - 9 4

- 3 6 - 7 - 8

9 5 8 4 1 6 -

3 - - - - 8 -

- 6 - 8 - 7 1

- Code: Select all
`Puzzle #2`

1 - - - 9 - -

5 7 9 - 1 6 8

- 3 8 5 - - -

9 - 7 - 8 - 3

- - - 1 - 7 9

- 9 4 8 - 1 -

4 5 - - - 8 -

- Code: Select all
`Puzzle #3`

7 - 4 6 5 - -

1 5 - 7 8 6 -

8 4 6 - - - 7

6 - - - 4 8 5

- - 5 8 6 7 1

5 - 7 - - 4 8

- - 8 4 7 5 6

- Code: Select all
`Puzzle #4`

8 9 5 4 - - 7

6 1 7 8 5 - -

9 5 4 6 - - -

7 6 - - - 4 -

- - - - 6 8 1

- 8 6 - 4 - -

4 7 - 9 8 5 6

- Code: Select all
`Puzzle #5`

- - - 4 - - -

- - - - 7 4 -

5 - 7 9 - 8 1

1 - 6 - - 7 -

7 8 - - 4 9 -

- 1 - 6 8 5 -

6 5 4 - - - -