●　たし算・ひき算を選びます。
●　問題は10問。
●　背景はプレイごとに変わるかも。（何種類かあります）
●　1ケタに限定可能です。

● Select the plus San pull calculated.
● problem is 10 questions.
● be background will vary for each play. (There are several types)
● it can be limited to a single digit.