Two Main Ideas and a Summary

1. Read "Bicycles in the City" aloud (text in the Teach section).
2. Ask for the main idea in one sentence. Expect: "Cycling is good for you."
3. Ask: which paragraphs does that cover? Paragraph 2, perhaps 3. What about 4 and 5? They are about dangerous streets and new lanes — the idea does not reach them.

“Your idea covers two paragraphs. Two more are sitting outside it. That is not a mistake in the text — it is a second main idea waiting for you.”

1. Display the text. (1) More people in cities are choosing to travel by bicycle, and city leaders are paying attention. (2) Cycling is good for riders' bodies. Someone who rides 20 minutes to school and 20 minutes home gets the daily exercise doctors recommend without setting aside time for it. (3) Bicycles also make a city better for people who never ride one. A bicycle gives off no fumes and makes almost no noise, so streets with more bicycles and fewer cars have cleaner air and are quieter. (4) But people will not cycle on streets that feel dangerous. In many cities a bike lane is only a painted line, and buses pass within a hand's width of riders. (5) Cities where cycling has grown fastest have built lanes separated from traffic by a raised curb and redesigned junctions so riders cross where drivers can see them. When these lanes open, the number of riders often rises within a year.
2. Fill the first row of the map: Main idea A — Cycling benefits a city, for riders' health and everyone's air and quiet. Paragraphs 2–3. Detail: "cleaner air and are quieter."
3. Fill the second row: Main idea B — People only cycle where streets are designed to protect them. Paragraphs 4–5. Detail: "separated from traffic by a raised curb."
4. Test a fake second idea: "Bicycles are healthy and good for the environment." Which paragraphs? 2–3 again — the same rows as A, so it is A reworded.
5. Test a forced one: "Buses drive close to riders." Which paragraphs? Half a sentence of paragraph 4. That is a detail, not an idea.
6. Write the summary: Cycling helps a city in two ways: riders get daily exercise, and streets with fewer cars are cleaner and quieter. But people only cycle where it feels safe, so the cities where cycling has grown have built curb-separated lanes and safer junctions.
7. Point out that each idea gets one sentence, and paragraph 1 — the introduction — gets none.

“A main idea needs paragraphs behind it. If your two ideas sit on the same paragraphs, they are one idea. If your idea sits on half a sentence, it is a detail.”

1. Display "Rooftop Gardens." (1) A roof covered in soil and plants soaks up the sun, so the rooms beneath it stay several degrees cooler in summer. (2) The soil also holds rainwater, so less water rushes into the drains during a storm. (3) But wet soil is very heavy, and many older roofs must be strengthened before a garden can be added. (4) The roof must also be waterproofed, and in dry summers the plants need watering, which adds to the cost.
2. Pairs complete the two-row map. Expected: A — Rooftop gardens help buildings and cities (cooler rooms, less flooding), paragraphs 1–2. B — They are difficult and costly to install and keep (weight, waterproofing, watering), paragraphs 3–4.
3. Each pair writes a two-sentence summary covering both ideas, then checks it against the map: does each row get a sentence?
4. Take one summary that covers only the benefits and ask the class which rows of the map it uses.

1. Students complete the printable main-ideas page alone. The passage is on the sheet.
2. Require the map before the summary: two ideas, paragraph numbers, one detail each.

1. Ask three students to give both main ideas of the rooftop text, one sentence each, and the paragraphs behind each.