Let's add and subtract!

转盘内容（15 个选项）

• 10 - 4 =
• 10 + 10 =
• 15 - 3 =
• 20 - 2 =
• 23 + 2 =
• 12 + 12 =
• 12 - 4 =
• 10 - 9 =
• 11 - 11 =
• 20 + 10 =
• 8 - 2 =
• 13 - 10 =
• 7 + 7 =
• 10 - 1 =
• 15 - 5 =