The Tool Library: Main Idea vs. Central Detail
Priya is practicing main-idea questions on a passage she wrote about a neighborhood tool library. The passage reads: “The library opened in a converted garage with 63 donated tools. Within eight months, 210 residents had borrowed a drill, ladder, or saw. Volunteers repaired 41 items and returned them to the shelves. Membership cost one dollar a year, and no one was turned away for missing the fee. The founder, a retired carpenter, said the goal was never to save money on tools but to make neighbors borrow from one another again.” Priya has narrowed her answer to (A) “A retired carpenter opens a tool library” and (B) “A small shared resource can strengthen community ties.” She favors A because it names a real person and event. Her tutor says A is accurate but too narrow. Priya wants a rule for separating a main idea from a vivid supporting detail, especially when the detail appears in the first and last sentences.
1. Why is B a stronger main idea than A, even though A is factually true?
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Conclusion: B is the main idea; A is a supporting detail.
The main idea must account for the whole passage, not just its most memorable sentence. A is true, but it covers only the opening situation and the founder. It does not explain why the passage includes 210 borrowers, 41 repaired items, a one-dollar membership, or the waiver of the fee. B covers all of those details: each shows a small shared resource producing participation and trust. The final sentence is the strongest signal because the founder explicitly says the goal “was never to save money” but to make neighbors “borrow from one another again.” That is a statement of purpose, which often carries the theme. A vivid detail can sit at the start or end and still be subordinate; ask whether the other sentences would be irrelevant without it. Here they would not be.
2. What function do the numbers 63, 210, 41, and one dollar serve in the passage?
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The numbers are evidence, not the idea. 63 donated tools establishes that the library started small and relied on giving. 210 residents in eight months shows adoption beyond a handful of neighbors. 41 repaired items shows maintenance and reciprocity-items were not merely taken. The one-dollar fee and the fee waiver show the library was designed for access, not profit. Together they support B by demonstrating that a modest shared resource changed how neighbors used and trusted one another. If the numbers were removed, B would still be possible, but it would be much weaker because the passage would offer only the founder’s assertion. If the numbers were changed to “3 tools and 4 residents,” B would collapse. That is the test: details should be replaceable in a summary, but not in the evidence.
3. If the final sentence were deleted, would B still be defensible? Explain.
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Yes, B would still be defensible, but it would require more inference. Without the final sentence, a reader would rely on the fee waiver, the donated tools, the repairs, and the borrowing patterns to infer that the library was about community rather than cheap storage. The final sentence makes the theme explicit, so deleting it would shift the passage from statement to implication. A careful reader could still choose B because the details form a pattern: people give, repair, and lend. However, A would become more tempting because the founder would no longer be quoted explaining a broader goal. The test is whether B can be supported by at least two or three separate details, not just one sentence. Here it can.