Arithmetic Puzzle Drills: Missing Digit and Cryptarithmetic Problems

This is a puzzle game combining "arithmetic with missing digits" (where you fill in blanks with numbers 0-9 in written calculations) and "cryptarithmetic" (where each hiragana character is replaced with a single digit) for iPhone. You can solve problems step by step, from basic addition and subtraction to advanced multiplication and division calculations.

• Each problem has exactly one answer
• Incorrect cells are marked, and if you get stuck, there's a "reveal one cell" hint (up to 2 times per problem)
• No time limit. After solving, you get a brief explanation of the solution
• 200 free problems, a daily problem at midnight, playable offline without internet, no account registration required

No ads appear while solving problems. There are optional problem packs for advanced and difficult problems (200 yen, which also removes ads) and an "remove ads" option (one-time purchase).