This is a "Crazy Number Game", connect the neighbouring numbers which less than 10, if sum of them is equal to 10, the last number you selected will be 10, if the number you selected is equal or more than 10, you can just connect it to one neighbouring number which is equal to you selected.
For example, if you connect 6、 3、 1 three number, the last selected 1 will change to 10 while you end touch the screen, and the numbers you selected previously will be random numbers.
You can use tools to switch two numbers, you can also +1 to one number or change it to 10.