[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 13 + 89", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "102"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Identity property", "Associative property", "Commutative property", "Distributive property"], "question": "Which property states a+0=a?", "difficulty": "easy", "explanation": "The identity property of addition states that adding 0 to any number gives that number.", "needs_review": false, "correct_answer": "Identity property"}, {"id": 3, "type": "short_answer", "skill": "computation", "question": "Calculate: 3 × 12", "difficulty": "medium", "explanation": "Multiply: 3×12=36", "needs_review": false, "correct_answer": "36"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 2 × 14", "difficulty": "medium", "explanation": "Multiply: 2×14=28", "needs_review": false, "correct_answer": "28"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 7 × 12", "difficulty": "medium", "explanation": "Multiply: 7×12=84", "needs_review": false, "correct_answer": "84"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 10 × 7", "difficulty": "medium", "explanation": "Multiply: 10×7=70", "needs_review": false, "correct_answer": "70"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 17 × 6", "difficulty": "medium", "explanation": "Multiply: 17×6=102", "needs_review": false, "correct_answer": "102"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 20 × 15", "difficulty": "medium", "explanation": "Multiply: 20×15=300", "needs_review": false, "correct_answer": "300"}, {"id": 9, "type": "short_answer", "skill": "computation", "question": "Calculate: 4 × 18", "difficulty": "medium", "explanation": "Multiply: 4×18=72", "needs_review": false, "correct_answer": "72"}, {"id": 10, "type": "short_answer", "skill": "computation", "question": "Calculate: 14 × 14", "difficulty": "medium", "explanation": "Multiply: 14×14=196", "needs_review": false, "correct_answer": "196"}, {"id": 11, "type": "short_answer", "skill": "computation", "question": "Calculate: 17 × 2", "difficulty": "medium", "explanation": "Multiply: 17×2=34", "needs_review": false, "correct_answer": "34"}, {"id": 12, "type": "short_answer", "skill": "computation", "question": "Calculate: 6 × 12", "difficulty": "medium", "explanation": "Multiply: 6×12=72", "needs_review": false, "correct_answer": "72"}]