[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 56 + 31", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "87"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Identity property", "Distributive property", "Associative property", "Commutative 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 × 6", "difficulty": "medium", "explanation": "Multiply: 3×6=18", "needs_review": false, "correct_answer": "18"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 8 × 16", "difficulty": "medium", "explanation": "Multiply: 8×16=128", "needs_review": false, "correct_answer": "128"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 14 × 5", "difficulty": "medium", "explanation": "Multiply: 14×5=70", "needs_review": false, "correct_answer": "70"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 13 × 12", "difficulty": "medium", "explanation": "Multiply: 13×12=156", "needs_review": false, "correct_answer": "156"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 20 × 12", "difficulty": "medium", "explanation": "Multiply: 20×12=240", "needs_review": false, "correct_answer": "240"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 20 × 3", "difficulty": "medium", "explanation": "Multiply: 20×3=60", "needs_review": false, "correct_answer": "60"}, {"id": 9, "type": "short_answer", "skill": "computation", "question": "Calculate: 19 × 13", "difficulty": "medium", "explanation": "Multiply: 19×13=247", "needs_review": false, "correct_answer": "247"}, {"id": 10, "type": "short_answer", "skill": "computation", "question": "Calculate: 12 × 12", "difficulty": "medium", "explanation": "Multiply: 12×12=144", "needs_review": false, "correct_answer": "144"}, {"id": 11, "type": "short_answer", "skill": "computation", "question": "Calculate: 14 × 19", "difficulty": "medium", "explanation": "Multiply: 14×19=266", "needs_review": false, "correct_answer": "266"}, {"id": 12, "type": "short_answer", "skill": "computation", "question": "Calculate: 9 × 4", "difficulty": "medium", "explanation": "Multiply: 9×4=36", "needs_review": false, "correct_answer": "36"}]