{
  "title": "Mental Math Strategies (Four Operations) - Grade 5 ICSE",
  "total_questions": 60,
  "questions": [
    {
      "id": 1,
      "difficulty": "easy",
      "question": "What is 25 + 47 using mental math? 🧠",
      "options": { "A": "62", "B": "72", "C": "82", "D": "92" },
      "correct_answer": "B"
    },
    {
      "id": 2,
      "difficulty": "easy",
      "question": "Calculate mentally: 100 - 38 = ?",
      "options": { "A": "52", "B": "62", "C": "72", "D": "82" },
      "correct_answer": "B"
    },
    {
      "id": 3,
      "difficulty": "easy",
      "question": "Mental addition: 63 + 29 = ? 🎯",
      "options": { "A": "82", "B": "92", "C": "102", "D": "112" },
      "correct_answer": "B"
    },
    {
      "id": 4,
      "difficulty": "easy",
      "question": "Subtract mentally: 85 - 47 = ?",
      "options": { "A": "28", "B": "38", "C": "48", "D": "58" },
      "correct_answer": "B"
    },
    {
      "id": 5,
      "difficulty": "easy",
      "question": "Double of 36 is? 🔢",
      "options": { "A": "62", "B": "72", "C": "82", "D": "92" },
      "correct_answer": "B"
    },
    {
      "id": 6,
      "difficulty": "easy",
      "question": "Half of 86 is? ✨",
      "options": { "A": "33", "B": "43", "C": "53", "D": "63" },
      "correct_answer": "B"
    },
    {
      "id": 7,
      "difficulty": "easy",
      "question": "Mental math: 17 × 5 = ? ⭐",
      "options": { "A": "75", "B": "85", "C": "95", "D": "105" },
      "correct_answer": "B"
    },
    {
      "id": 8,
      "difficulty": "easy",
      "question": "Quick calculation: 24 × 4 = ? 🎈",
      "options": { "A": "86", "B": "96", "C": "106", "D": "116" },
      "correct_answer": "B"
    },
    {
      "id": 9,
      "difficulty": "easy",
      "question": "Divide mentally: 84 ÷ 4 = ?",
      "options": { "A": "18", "B": "21", "C": "24", "D": "27" },
      "correct_answer": "B"
    },
    {
      "id": 10,
      "difficulty": "easy",
      "question": "Mental addition: 125 + 75 = ? 🎪",
      "options": { "A": "180", "B": "190", "C": "200", "D": "210" },
      "correct_answer": "C"
    },
    {
      "id": 11,
      "difficulty": "easy",
      "question": "Subtract quickly: 200 - 63 = ?",
      "options": { "A": "127", "B": "137", "C": "147", "D": "157" },
      "correct_answer": "B"
    },
    {
      "id": 12,
      "difficulty": "easy",
      "question": "Double 125 is? 🚀",
      "options": { "A": "225", "B": "250", "C": "275", "D": "300" },
      "correct_answer": "B"
    },
    {
      "id": 13,
      "difficulty": "easy",
      "question": "Half of 150 is? 🏆",
      "options": { "A": "65", "B": "70", "C": "75", "D": "80" },
      "correct_answer": "C"
    },
    {
      "id": 14,
      "difficulty": "easy",
      "question": "Multiply mentally: 15 × 6 = ? 🎮",
      "options": { "A": "80", "B": "90", "C": "100", "D": "110" },
      "correct_answer": "B"
    },
    {
      "id": 15,
      "difficulty": "easy",
      "question": "Quick division: 96 ÷ 8 = ? 📚",
      "options": { "A": "10", "B": "11", "C": "12", "D": "13" },
      "correct_answer": "C"
    },
    {
      "id": 16,
      "difficulty": "easy",
      "question": "Add mentally: 88 + 44 = ? 🌈",
      "options": { "A": "122", "B": "132", "C": "142", "D": "152" },
      "correct_answer": "B"
    },
    {
      "id": 17,
      "difficulty": "easy",
      "question": "Subtract: 156 - 78 = ? 🎯",
      "options": { "A": "68", "B": "78", "C": "88", "D": "98" },
      "correct_answer": "B"
    },
    {
      "id": 18,
      "difficulty": "easy",
      "question": "Double 99 is? 🎁",
      "options": { "A": "188", "B": "198", "C": "208", "D": "218" },
      "correct_answer": "B"
    },
    {
      "id": 19,
      "difficulty": "easy",
      "question": "Half of 196 is? 🍎",
      "options": { "A": "88", "B": "98", "C": "108", "D": "118" },
      "correct_answer": "B"
    },
    {
      "id": 20,
      "difficulty": "easy",
      "question": "Mental math: 25 × 8 = ? ⏰",
      "options": { "A": "150", "B": "175", "C": "200", "D": "225" },
      "correct_answer": "C"
    },

    {
      "id": 21,
      "difficulty": "medium",
      "question": "Calculate mentally: 47 × 99 using complement method 🧠",
      "options": { "A": "4653", "B": "4753", "C": "4853", "D": "4953" },
      "correct_answer": "A"
    },
    {
      "id": 22,
      "difficulty": "medium",
      "question": "Mental addition: 298 + 397 = ? 🎪",
      "options": { "A": "685", "B": "695", "C": "705", "D": "715" },
      "correct_answer": "B"
    },
    {
      "id": 23,
      "difficulty": "medium",
      "question": "Subtract quickly: 1000 - 367 = ? 🚀",
      "options": { "A": "623", "B": "633", "C": "643", "D": "653" },
      "correct_answer": "B"
    },
    {
      "id": 24,
      "difficulty": "medium",
      "question": "Multiply: 24 × 25 using quarter method ⭐",
      "options": { "A": "500", "B": "550", "C": "600", "D": "650" },
      "correct_answer": "C"
    },
    {
      "id": 25,
      "difficulty": "medium",
      "question": "Divide mentally: 225 ÷ 15 = ? 🎯",
      "options": { "A": "12", "B": "13", "C": "14", "D": "15" },
      "correct_answer": "D"
    },
    {
      "id": 26,
      "difficulty": "medium",
      "question": "Add using compensation: 497 + 256 = ? ✨",
      "options": { "A": "743", "B": "753", "C": "763", "D": "773" },
      "correct_answer": "B"
    },
    {
      "id": 27,
      "difficulty": "medium",
      "question": "Subtract using adjustment: 803 - 299 = ? 🔢",
      "options": { "A": "494", "B": "504", "C": "514", "D": "524" },
      "correct_answer": "B"
    },
    {
      "id": 28,
      "difficulty": "medium",
      "question": "Multiply mentally: 18 × 15 = ? 🎈",
      "options": { "A": "250", "B": "260", "C": "270", "D": "280" },
      "correct_answer": "C"
    },
    {
      "id": 29,
      "difficulty": "medium",
      "question": "Quick division: 392 ÷ 14 = ? 📚",
      "options": { "A": "26", "B": "27", "C": "28", "D": "29" },
      "correct_answer": "C"
    },
    {
      "id": 30,
      "difficulty": "medium",
      "question": "Add: 375 + 425 = ? 🏆",
      "options": { "A": "790", "B": "800", "C": "810", "D": "820" },
      "correct_answer": "B"
    },
    {
      "id": 31,
      "difficulty": "medium",
      "question": "Subtract: 750 - 275 = ? 🎮",
      "options": { "A": "465", "B": "475", "C": "485", "D": "495" },
      "correct_answer": "B"
    },
    {
      "id": 32,
      "difficulty": "medium",
      "question": "Multiply: 32 × 125 using factor method 🧩",
      "options": { "A": "3500", "B": "3750", "C": "4000", "D": "4250" },
      "correct_answer": "C"
    },
    {
      "id": 33,
      "difficulty": "medium",
      "question": "Divide: 648 ÷ 24 = ? 🌈",
      "options": { "A": "25", "B": "26", "C": "27", "D": "28" },
      "correct_answer": "C"
    },
    {
      "id": 34,
      "difficulty": "medium",
      "question": "Add mentally: 567 + 333 = ? 🎪",
      "options": { "A": "890", "B": "900", "C": "910", "D": "920" },
      "correct_answer": "B"
    },
    {
      "id": 35,
      "difficulty": "medium",
      "question": "Subtract: 921 - 478 = ? 🚀",
      "options": { "A": "433", "B": "443", "C": "453", "D": "463" },
      "correct_answer": "B"
    },
    {
      "id": 36,
      "difficulty": "medium",
      "question": "Multiply quickly: 45 × 11 = ? ⭐",
      "options": { "A": "485", "B": "495", "C": "505", "D": "515" },
      "correct_answer": "B"
    },
    {
      "id": 37,
      "difficulty": "medium",
      "question": "Divide mentally: 735 ÷ 15 = ? 🎯",
      "options": { "A": "47", "B": "48", "C": "49", "D": "50" },
      "correct_answer": "C"
    },
    {
      "id": 38,
      "difficulty": "medium",
      "question": "Add using doubles: 149 + 151 = ? ✨",
      "options": { "A": "290", "B": "300", "C": "310", "D": "320" },
      "correct_answer": "B"
    },
    {
      "id": 39,
      "difficulty": "medium",
      "question": "Subtract using complements: 1002 - 498 = ? 🔢",
      "options": { "A": "494", "B": "504", "C": "514", "D": "524" },
      "correct_answer": "B"
    },
    {
      "id": 40,
      "difficulty": "medium",
      "question": "Multiply: 16 × 75 = ? 🎈",
      "options": { "A": "1100", "B": "1150", "C": "1200", "D": "1250" },
      "correct_answer": "C"
    },

    {
      "id": 41,
      "difficulty": "hard",
      "question": "Mental calculation: 48 × 125 = ? 🧠",
      "options": { "A": "5500", "B": "5750", "C": "6000", "D": "6250" },
      "correct_answer": "C"
    },
    {
      "id": 42,
      "difficulty": "hard",
      "question": "Add quickly: 876 + 234 + 567 = ? 🎪",
      "options": { "A": "1567", "B": "1677", "C": "1777", "D": "1877" },
      "correct_answer": "B"
    },
    {
      "id": 43,
      "difficulty": "hard",
      "question": "Subtract mentally: 2003 - 987 = ? 🚀",
      "options": { "A": "1006", "B": "1016", "C": "1026", "D": "1036" },
      "correct_answer": "B"
    },
    {
      "id": 44,
      "difficulty": "hard",
      "question": "Multiply using factors: 36 × 25 × 4 = ? ⭐",
      "options": { "A": "3400", "B": "3500", "C": "3600", "D": "3700" },
      "correct_answer": "C"
    },
    {
      "id": 45,
      "difficulty": "hard",
      "question": "Divide: 1728 ÷ 36 = ? 🎯",
      "options": { "A": "46", "B": "47", "C": "48", "D": "49" },
      "correct_answer": "C"
    },
    {
      "id": 46,
      "difficulty": "hard",
      "question": "Add using grouping: 299 + 397 + 498 = ? ✨",
      "options": { "A": "1184", "B": "1194", "C": "1204", "D": "1214" },
      "correct_answer": "B"
    },
    {
      "id": 47,
      "difficulty": "hard",
      "question": "Subtract: 5000 - 2345 = ? 🔢",
      "options": { "A": "2555", "B": "2655", "C": "2755", "D": "2855" },
      "correct_answer": "B"
    },
    {
      "id": 48,
      "difficulty": "hard",
      "question": "Multiply mentally: 125 × 32 = ? 🎈",
      "options": { "A": "3750", "B": "4000", "C": "4250", "D": "4500" },
      "correct_answer": "B"
    },
    {
      "id": 49,
      "difficulty": "hard",
      "question": "Divide quickly: 2025 ÷ 45 = ? 📚",
      "options": { "A": "43", "B": "44", "C": "45", "D": "46" },
      "correct_answer": "C"
    },
    {
      "id": 50,
      "difficulty": "hard",
      "question": "Add: 1234 + 876 + 567 = ? 🏆",
      "options": { "A": "2567", "B": "2677", "C": "2777", "D": "2877" },
      "correct_answer": "B"
    },
    {
      "id": 51,
      "difficulty": "hard",
      "question": "Subtract using adjustment: 3001 - 1499 = ? 🎮",
      "options": { "A": "1402", "B": "1502", "C": "1602", "D": "1702" },
      "correct_answer": "B"
    },
    {
      "id": 52,
      "difficulty": "hard",
      "question": "Multiply: 88 × 125 = ? 🧩",
      "options": { "A": "10500", "B": "11000", "C": "11500", "D": "12000" },
      "correct_answer": "B"
    },
    {
      "id": 53,
      "difficulty": "hard",
      "question": "Divide mentally: 3136 ÷ 56 = ? 🌈",
      "options": { "A": "54", "B": "55", "C": "56", "D": "57" },
      "correct_answer": "C"
    },
    {
      "id": 54,
      "difficulty": "hard",
      "question": "Add: 1587 + 2345 + 987 = ? 🎪",
      "options": { "A": "4819", "B": "4919", "C": "5019", "D": "5119" },
      "correct_answer": "B"
    },
    {
      "id": 55,
      "difficulty": "hard",
      "question": "Subtract: 8000 - 3765 = ? 🚀",
      "options": { "A": "4135", "B": "4235", "C": "4335", "D": "4435" },
      "correct_answer": "B"
    },
    {
      "id": 56,
      "difficulty": "hard",
      "question": "Multiply using complement: 98 × 97 = ? ⭐",
      "options": { "A": "9406", "B": "9506", "C": "9606", "D": "9706" },
      "correct_answer": "B"
    },
    {
      "id": 57,
      "difficulty": "hard",
      "question": "Divide: 4096 ÷ 64 = ? 🎯",
      "options": { "A": "62", "B": "63", "C": "64", "D": "65" },
      "correct_answer": "C"
    },
    {
      "id": 58,
      "difficulty": "hard",
      "question": "Add using approximation: 2987 + 1998 + 2999 = ? ✨",
      "options": { "A": "7884", "B": "7984", "C": "8084", "D": "8184" },
      "correct_answer": "B"
    },
    {
      "id": 59,
      "difficulty": "hard",
      "question": "Subtract mentally: 10000 - 5678 = ? 🔢",
      "options": { "A": "4222", "B": "4322", "C": "4422", "D": "4522" },
      "correct_answer": "B"
    },
    {
      "id": 60,
      "difficulty": "hard",
      "question": "Multiply: 144 × 25 = ? 🎈",
      "options": { "A": "3400", "B": "3500", "C": "3600", "D": "3700" },
      "correct_answer": "C"
    }
  ]
}