[{"id": 1, "type": "short_answer", "skill": "subtraction", "question": "Calculate: 146 − 43", "difficulty": "medium", "explanation": "Subtract by place value, borrowing as needed.", "needs_review": false, "correct_answer": "103"}, {"id": 2, "type": "multiple_choice", "skill": "subtraction", "options": ["101", "103", "189", "104"], "question": "What is 146 − 43?", "difficulty": "easy", "explanation": "146-43=103", "needs_review": false, "correct_answer": "103"}, {"id": 3, "type": "short_answer", "skill": "computation", "question": "Calculate: 12 × 7", "difficulty": "medium", "explanation": "Multiply: 12×7=84", "needs_review": false, "correct_answer": "84"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 4 × 16", "difficulty": "medium", "explanation": "Multiply: 4×16=64", "needs_review": false, "correct_answer": "64"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 20 × 11", "difficulty": "medium", "explanation": "Multiply: 20×11=220", "needs_review": false, "correct_answer": "220"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 12 × 18", "difficulty": "medium", "explanation": "Multiply: 12×18=216", "needs_review": false, "correct_answer": "216"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 2 × 15", "difficulty": "medium", "explanation": "Multiply: 2×15=30", "needs_review": false, "correct_answer": "30"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 5 × 5", "difficulty": "medium", "explanation": "Multiply: 5×5=25", "needs_review": false, "correct_answer": "25"}]