What is Kakuro?

Just like Sudoku, Kakuro is a fun brain teasing game that will make you think. Do you want to find out how smart you're? Try Kakuro and learn to solve problems and identify patterns using simple logic! Perfect for a fun-loving family. Spend quality time with your children and help them become smarter.

How Kakuro Works?

Well, Kakuro is made up of a grid of boxes. First row and first column contain numbers but the remaining boxes are empty. And yes you've guessed it right, you have to fill the empty boxes. But how? Let's see.

Here's the secret. The numbers in the first row and column aren't just numbers. They're also the hints! You have to fill the empty boxes using numbers between 1 and 9 in such a way that sum of the boxes from left to right and the sum of the boxes from top to bottom equal the hints.

Easy, right? Here's the challenge. You can't use the same number twice in a single vertical or horizontal line of boxes. But you can use that number in the neighboring line of boxes.

How to Solve Kakuro Puzzle?

Look at the first picture. Observe the second vertical grid which is highlighted. It has a hint 4 with a downwards arrow. It means you need to think of two numbers the sum of which is 4. There are 3 possibilities:

0 and 4. But we can only use digits between 1 and 9!

2 and 2. Right? No! Because we can't use same numbers twice in the same grid.

3 and 1. We've found a solution!

Let's put the numbers in. Now, we've the second picture.

We've to repeat what we did above. This time we will need to check our solution for both vertical and horizontal grids.

You can see we need to find a number that when added up with 1 makes 12. There's only one number that can do that. It's 11. Hey, that can't be right. We can only use numbers between 1 and 9.

Hmm... Did we do something wrong?

Yes! We put 1 and 3 in the wrong order. Let's try again by flipping them. In the top box, we are going to put 3 and in the bottom box, we put 1.

The grid looks like the picture 3.

Now, let's give it another go. What number should be added with 3 so the total sum is 12? That's 9!

Let's put 9 in there. We've only one box left to fill. But the last box is always the easiest!

Just subtract your solutions from the hint! What is 12 - 9 or 4 - 1? It's 3!

We did it! See how everything checks out.

Congratulations! You've solved your first Kakuro puzzle.

Let's Increase the Difficulty

Two grids are easy peasy! Let's give three grid Kakuro a shot. When solving a more challenging Kakuro puzzle, try to find out a grid which has the smallest number of combinations for a correct solution.

Look at the first picture. The first horizontal grid has only one correct solution! That's 6+8+9 which equals 23.

Hint: Hey, keep in mind that the smaller number doesn't necessarily have the least number of combinations. For example, 23 only has one correct combination but 9 has more!

Now, we know the solution for 23. But, how to fill the boxes?

Can we put 9 in the column where the hint is 9? No! Because then the only way to fill the grid would be to put two zeros and we can only use numbers between 1 and 9.

Can we put 8 there? Still no! Why? Because then we will need to put 1 and 0 to get the right sum of 9. And again, we can't use zero.

So, the only number that can go under the hint 9 is 6!

Now, let's learn a new method to solve Kakuro! We call it Min-Max Intersection.

Take a look at the picture below. The last hint in the horizontal grid is 7. It also has a single unique combination like 23!

The only way we get 7 is by adding 1, 2 and 4. Any other combination of numbers doesn't follow the rules of the game.

Now, think hard. If we can only use 1, 2 and 4 as a solution, it means the biggest number that we can put in the bottom horizontal grid is 4!

Looking at the vertical grid hints, you may think there can be many other numbers that we can use. For example, the first vertical hint 20 has 4 different solutions.

1. 3+8+9 = 20

2. 4+7+9 = 20

3. 5+7+8 = 20

4. 5+6+9 = 20

But we can't use any of them except 4. Using 5, 6 or 7 will mean we'll have to break the rules of Kakuro to find a correct solution. And 3 doesn't fit the solution!

That's why we can only use 4 in the intersecting box!

Let's move on. We've figured out two combinations:

For 23, we have 6, 8 and 9. For 20, we have 4, 7 and 9. From each of the combinations we have used the first ones.

Now, we're only left with 8 and 9 from 23. And 7 and 9 from 20. You can fill the grid with the remaining numbers!

There is another trick we call cell exclusion.

With the hint 7, we've two empty boxes and the remaining possible numbers are 1 and 2.

We can't put 2 first because then we will need another 8 on the top of 2. And repetition isn't allowed within the same grid, remember?

So we put 1 first and then 2. See how it works out!

You must already be feeling smarter! Let's play!