The mathematician’s ultimate crossword, this application is great for anyone wishing to enhance your mathematical skills and is loved by math geeks around the digital world. You can often find versions of Kakuro puzzles featured anywhere that is published involving mathematics and often science. Each word in the crossword puzzle can only use numbers 1 though 9 and you must find each “word” using the clues listed either above or to the left of each piece of the puzzle. The goal is to complete all of the spaces on the grid so that the numbers you enter add up to the clues given. You must use your logical skills to solve each puzzle as there is only one correct answer for each grid. With over 14,000 individual games you will find yourself challenged for hours on end. Math has never been this fun. Game available on Google Play and Amazon.