[{"id": 1, "type": "short_answer", "skill": "computation", "question": "Calculate: 47 + 89", "difficulty": "medium", "explanation": "Add systematically.", "needs_review": false, "correct_answer": "136"}, {"id": 2, "type": "multiple_choice", "skill": "properties", "options": ["Identity property", "Distributive property", "Commutative property", "Associative 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: 10 × 20", "difficulty": "medium", "explanation": "Multiply: 10×20=200", "needs_review": false, "correct_answer": "200"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 14 × 13", "difficulty": "medium", "explanation": "Multiply: 14×13=182", "needs_review": false, "correct_answer": "182"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 17 × 12", "difficulty": "medium", "explanation": "Multiply: 17×12=204", "needs_review": false, "correct_answer": "204"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 19 × 10", "difficulty": "medium", "explanation": "Multiply: 19×10=190", "needs_review": false, "correct_answer": "190"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 11 × 7", "difficulty": "medium", "explanation": "Multiply: 11×7=77", "needs_review": false, "correct_answer": "77"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 6 × 7", "difficulty": "medium", "explanation": "Multiply: 6×7=42", "needs_review": false, "correct_answer": "42"}, {"id": 9, "type": "short_answer", "skill": "computation", "question": "Calculate: 15 × 5", "difficulty": "medium", "explanation": "Multiply: 15×5=75", "needs_review": false, "correct_answer": "75"}, {"id": 10, "type": "short_answer", "skill": "computation", "question": "Calculate: 4 × 4", "difficulty": "medium", "explanation": "Multiply: 4×4=16", "needs_review": false, "correct_answer": "16"}, {"id": 11, "type": "short_answer", "skill": "computation", "question": "Calculate: 14 × 20", "difficulty": "medium", "explanation": "Multiply: 14×20=280", "needs_review": false, "correct_answer": "280"}, {"id": 12, "type": "short_answer", "skill": "computation", "question": "Calculate: 10 × 15", "difficulty": "medium", "explanation": "Multiply: 10×15=150", "needs_review": false, "correct_answer": "150"}]