Kakooma: Power Adding Puzzle

Kakooma is a wonderful puzzle created by mathematician, Greg Tang, to challenge children to see the operations visually requiring hundreds of mental calculations and strategies. 

We used a 9x9 array of numbers separated into nine 3x3 squares. Each 3x3 square contains nine numbers. Your objective is to find the one number that is the sum of two others and write the answer in the corresponding 3x3 empty box below to large array. Repeat the steps for the other eight 3x3 boxes and record the sum in the empty 3x3 box below in the corresponding place. Finally, find the sum in the 3x3 box below and you have solved the puzzle.

I separated these into Basic, Intermediate and Advanced level. The 1-2nd graders should work with the pdf dealing with Basic and Intermediate and the 3-7th graders with levels Intermediate and Advanced. There are many strategies to use: a) random checking for two numbers that add up to a third number, b) choose the smallest number in the box and find two other numbers that have that difference (for example, if the smallest number is 3, look for numbers like 15 and 18, then you know that 18 is your sum of 3 + 15), c) add the smallest number to the next smallest number, then the next smallest until you find the sum, and my favorite is d) add the ones digit of any two numbers and look for the ones digit in a third number.

The new challenge that I introduced this year was for the children to make their own Kakooma. This proved harder than expected. When they challenged me to solve their puzzle and I found the solution, they also found multiple solutions in the same square. The trick is to create the puzzle so the answer is not obvious but avoid two solutions.

I can’t wait to try the puzzles your children make this week.