Overview

Lesson Procedure

55-65 minutes of class time across 5 phases.

1. Warm-Up5-10 minutes
2. Direct Instruction15 minutes
3. Guided Practice15 minutes
4. Independent Practice15-20 minutes
5. Closure5 minutes

1. Warm-Up5-10 minutes

   Project the prompt, a made-up note from a school weather station. Give students two minutes to mark it up.

   Warm-Up Prompt

   Weather station note: "Between 2 p.m. and 5 p.m. the air pressure fell steadily, the wind shifted from west to south, and the clouds thickened. By 6 p.m. it was raining." A student sums it up: "The weather got bad and ruined my soccer game, because falling pressure always means a storm." Underline the parts of the student's sentence that come from the note. Circle the opinion. Box the part the student already knew from somewhere else.

   Take answers. From the note: the weather changed and it rained. Opinion: "ruined my soccer game." Prior knowledge: "falling pressure always means a storm," which the note never says (and "always" is too strong). A fair one-sentence summary is "Over the afternoon the pressure fell, the wind shifted and the clouds thickened, and by evening it was raining." Tell students that RST.6-8.2 asks for two things: find the central ideas or conclusions of a science text, and write a summary that reports the text, not what the reader thinks or already knew.

2. Direct Instruction15 minutes

   Part 1: The words of summarizing. Keep this table up for the whole lesson.

   Words for central ideas and summaries

   Term	What it means	Example from Passage 1
   Topic	What the text is about, in a few words	Oil on a windy pond
   Central idea	The most important point the whole text makes about the topic	A little oil, put in the right place, calms a large area of rough water.
   Conclusion	What the author decides from the evidence of an experiment	The oil works on the windward side, not the leeward side.
   Supporting detail	A fact, number or event that backs up the central idea	"not more than a tea spoonful"
   Summary	A short restatement, in your own words, of the central idea and the key details, in the text's order	Three or four sentences, not the whole passage
   Prior knowledge / opinion	What the reader already knew from somewhere else / what the reader thinks or feels about it	"Oil floats on water." / "This was a brilliant idea."

   Part 2: Model with Passage 1. Benjamin Franklin, the American printer, scientist and statesman, lived in London for many years before the American Revolution. In 1773 he wrote a letter to a doctor and scientist, William Brownrigg, describing what he had learned about calming waves with oil, and the Royal Society in London printed it in 1774. Words to know: common (a public park), cruet (a small bottle, like one for salad oil), dropt (old spelling of dropped), leeward (the side the wind blows toward), windward (the side the wind comes from), lee side (the leeward side), looking-glass (a mirror), contrived (arranged). Read the passage aloud once, then work the three examples. Diagram 1 shows Example 1, and Diagram 2 shows how to sort sentences for Example 3.

   1At length being at Clapham, where there is, on the common, a large pond, which I observed one day to be very rough with the wind, I fetched out a cruet of oil, and dropt a little of it on the water. I saw it spread itself with surprising swiftness upon the surface; but the effect of smoothing the waves was not produced; for I had applied it first on the leeward side of the pond, where the waves were largest, and the wind drove my oil back upon the shore. I then went to the windward side where they began to form; and there the oil, though not more than a tea spoonful, produced an instant calm over a space several yards square, which spread amazingly, and extended itself gradually till it reached the lee side, making all that quarter of the pond, perhaps half an acre, as smooth as a looking-glass.

   2After this I contrived to take with me, whenever I went into the country, a little oil in the upper hollow joint of my bamboo cane, with which I might repeat the experiment as opportunity should offer, and I found it constantly to succeed.

   • Finding the central idea

     Read Passage 1. What is its topic, and what is the central idea? Name the details that support it.

     Result: Topic: oil on a windy pond. Central idea: a little oil, put where the waves begin to form, can calm a large area of rough water, and it works again and again. Support: the oil, "though not more than a tea spoonful, produced an instant calm over a space several yards square," which spread to "perhaps half an acre" (paragraph 1), and when Franklin repeated it he "found it constantly to succeed" (paragraph 2). The small amount compared with the large area is what makes the result worth reporting.

   • Finding a conclusion from a failed first try

     Franklin's first try at Clapham did not work. What does he conclude from it, and how can you tell?

     Result: He concludes that the oil must go on the windward side, where the waves start. The first time, "the effect of smoothing the waves was not produced; for I had applied it first on the leeward side," and "the wind drove my oil back upon the shore" (paragraph 1). He then "went to the windward side where they began to form," and it worked. The word "for" introduces his reason, and the change he makes next shows the conclusion he drew.

   • Writing an accurate summary

     Write a three-sentence summary of Passage 1. Then check it against the rules: central idea first, key details in order, your own words, no opinion, nothing from outside the text.

     Result: Summary: Franklin dropped a little oil on a pond at Clapham on a windy day. Oil put on the side the wind blew toward was pushed back to shore, but about a teaspoon put on the side where the waves began calmed a large area, perhaps half an acre. He carried oil in his cane and found that the experiment worked each time he repeated it. Not allowed: "Franklin was brilliant" (opinion) or "because oil is lighter than water" (prior knowledge; the passage never gives a reason).

3. Guided Practice15 minutes

   Pairs read Passage 2, which comes right after Passage 1 in the letter. Words to know: forcible (strong), hitherto (until now), prismatic colours (rainbow colors), mutual repulsion (pushing away from each other), recede (move back), ascertained (found out for certain), whence it arises (where it comes from). Passage 2 is one paragraph, so students cite it as (Passage 2).

   1In these experiments, one circumstance struck me with particular surprise. This was the sudden, wide and forcible spreading of a drop of oil on the face of the water, which I do not know that any body has hitherto considered. If a drop of oil is put on a highly polished marble table, or on a looking-glass that lies horizontally, the drop remains in its place, spreading very little. But when put on water, it spreads instantly many feet round, becoming so thin as to produce the prismatic colours, for a considerable space, and beyond them so much thinner as to be invisible, except in its effect of smoothing the waves at a much greater distance. It seems as if a mutual repulsion between its particles took place as soon as it touched the water, and a repulsion so strong as to act on other bodies swimming on the surface, as straw, leaves, chips, &c. forcing them to recede every way from the drop, as from a centre, leaving a large clear space. The quantity of this force, and the distance to which it will operate, I have not yet ascertained; but I think it a curious enquiry, and I wish to understand whence it arises.

   Pairs highlight the central idea in one color and the details that support it in another, then write the central idea in one sentence before you show the example.

   • Central idea and the details a summary needs

     Pairs read Passage 2 and write its central idea in one sentence. Then they choose the details a summary must keep.

     Result: Central idea: on water, a drop of oil spreads suddenly and very widely, which it does not do on a hard, smooth surface, as if some force pushes it outward, and Franklin does not yet know the cause. Details to keep: on "a highly polished marble table" the drop "remains in its place"; on water "it spreads instantly many feet round"; the film turns too thin to see but still smooths waves; the drop pushes "straw, leaves, chips, &c." away; and he has "not yet ascertained" the force. "It seems as if" shows his explanation is a guess, so a summary should say "Franklin suggests," not "Franklin proves."

   Debrief: Which sentence of Passage 2 shows that Franklin himself is not sure? ("It seems as if..." and "I have not yet ascertained.") An accurate summary keeps the author's certainty level: it does not turn a guess into a fact. Then hand out Passage 3, three summaries written for this page, for Activity 2.

   1Summary A. Franklin notices that a drop of oil behaves very differently on water than on a hard, smooth surface. On a polished marble table or a flat mirror, the drop stays where it is and spreads very little. On water, it spreads many feet at once, first into a film thin enough to show rainbow colors and then into a film too thin to see, which still smooths waves farther away. The spreading oil also pushes floating straws, leaves and chips away from it. Franklin suggests that the oil's particles push away from one another, but he says he has not yet measured this force and wants to learn where it comes from.

   2Summary B. Franklin's discovery is amazing, and he was a genius for noticing it. He shows that oil spreads fast on water but not on a table. This is the best part of his whole letter, and everyone should try it in the kitchen sink tonight.

   3Summary C. Franklin explains that oil spreads on water because oil is less dense than water, so it floats. Today we know that the film is only about one molecule thick. The oil spreads many feet and pushes straws and leaves away. On marble or glass the drop stays put.

4. Independent Practice15-20 minutes

   Students read Passages 4 and 5 on their own and answer quiz questions 1-20 with the passages open. Passage 4 is Franklin's explanation of how wind makes waves and how oil prevents them. Words to know: endeavour (try), imbibe (take in), air-pump (a pump that removes air from a container), subside (sink down), magnitude (size), catch (grip), friction (rubbing that slows motion), to leeward (toward the side the wind blows toward). Passage 5 is a short modern explanation written for this page.

   1This prevention I would thus endeavour to explain.

   2There seems to be no natural repulsion between water and air, such as to keep them from coming into contact with each other. Hence we find a quantity of air in water; and if we extract it by means of the air-pump, the same water, again exposed to the air, will soon imbibe an equal quantity.

   3Therefore air in motion, which is wind, in passing over the smooth surface of water, may rub, as it were, upon that surface, and raise it into wrinkles, which, if the wind continues, are the elements of future waves.

   4The smallest wave once raised does not immediately subside, and leave the neighbouring water quiet: but in subsiding raises nearly as much of the water next to it, the friction of the parts making little difference. Thus a stone dropped in a pool raises first a single wave round itself; and leaves it, by sinking to the bottom; but that first wave subsiding raises a second, the second a third, and so on in circles to a great extent.

   5A small power continually operating will produce a great action. A finger applied to a weighty suspended bell can at first move it but little; if repeatedly applied, though with no greater strength, the motion increases till the bell swings to its utmost height, and with a force that cannot be resisted by the whole strength of the arm and body. Thus the small first-raised waves, being continually acted upon by the wind, are, though the wind does not increase in strength, continually increased in magnitude, rising higher and extending their bases, so as to include a vast mass of water in each wave, which in its motion acts with great violence.

   [...]

   6Now I imagine that the wind, blowing over water thus covered with a film of oil, cannot easily catch upon it, so as to raise the first wrinkles, but slides over it, and leaves it smooth as it finds it. It moves a little the oil indeed, which being between it and the water, serves it to slide with, and prevents friction, as oil does between those parts of a machine, that would otherwise rub hard together. Hence the oil dropped on the windward side of a pond proceeds gradually to leeward, as may be seen by the smoothness it carries with it, quite to the opposite side. For the wind being thus prevented from raising the first wrinkles, that I call the elements of waves, cannot produce waves, which are to be made by continually acting upon, and enlarging those elements, and thus the whole pond is calmed.

   1Water molecules pull on one another. At the surface, this pull makes water act a little like a stretched sheet, and scientists call it surface tension.

   2A drop of olive oil on clean water does not stay a drop. The clean water around it pulls on the edge of the oil harder than the oil pulls back, so the edge is drawn outward and the drop spreads in seconds into a film. The film keeps spreading until it is only a few billionths of a meter thick, close to the size of a single oil molecule. Franklin's own numbers show how thin that is: if his teaspoon held about 5 milliliters and half an acre is about 2,000 square meters, the layer was about 2.5 billionths of a meter thick.

   3Wind makes waves in two stages. First it raises tiny ripples, only millimeters high. Then it keeps pushing on those ripples, and they grow into larger waves. An oil film changes how the water's surface stretches, so the tiny ripples die out almost as soon as they form. With no ripples to push on, the wind cannot build waves in the oiled area.

   4The film does not quickly stop a wave that is already large, because a large wave keeps moving long after the wind that made it has died down. Oil spills harm birds, fish and plants, so no one should pour oil into a pond or the sea to test any of this.

5. Closure5 minutes

   Exit ticket: "In one sentence, state the central idea of any passage from today. Then write one sentence that would NOT belong in a summary of it, and say whether it is an opinion or prior knowledge." Sort the tickets into "central idea stated accurately," "a detail given as the central idea" and "opinion or outside fact mixed in."

   Teacher note on the science and the language. Franklin's observations are accurate, and modern science agrees with the main point of his explanation of the calm (Passage 5 gives today's version). His reason for the spreading (Passage 2 and the paragraph cut from Passage 4) is not today's explanation; Passage 5 gives the modern one. Later scientists used Franklin's own numbers to estimate how thin the film is, as Passage 5 does. Please do not pour oil into ponds, streams or the sea: oil harms wildlife. The letter uses 18th-century spelling and punctuation (dropt, tea spoonful, colours, "&c." for etc.), kept exactly as printed.

   Homework passage. Passage 6 describes a trial Franklin ran in October 1773 off Portsmouth, a navy port on the south coast of England, to see whether oil poured at sea could calm the surf (the waves breaking on the shore). Words to know: lee-shore (a shore the wind blows toward), the Centaur (a navy ship), long-boat and barge (a ship's rowing boats), our disposition (how we arranged ourselves), plied (went back and forth), stone-bottle (a heavy pottery bottle), goose-quill (a feather pen), material (important), tract (a long strip), swell (long, smooth waves), wherry (a small boat), turnpike-road (a main road), amendment (improvement), apprehend (think).

   1[...] Accordingly, about the middle of October last, I went with some friends to Portsmouth; and a day of wind happening, which made a lee-shore between Haslar-hospital and the point near Jillkecker, we went from the Centaur with the long-boat and barge towards that shore. Our disposition was this: the long-boat was anchored about a quarter of a mile from the shore; part of the company were landed behind the point (a place more sheltered from the sea) who came round and placed themselves opposite to the long-boat, where they might observe the surf, and note if any change occurred in it upon using the oil. Another party, in the barge, plied to windward of the long-boat, as far from her as she was from the shore, making trips of about half a mile each, pouring oil continually out of a large stone-bottle, through a hole in the cork, somewhat bigger than a goose-quill. The experiment had not, in the main point, the success we wished, for no material difference was observed in the height or force of the surf upon the shore; but those who were in the long-boat could observe a tract of smoothed water, the whole of the distance in which the barge poured the oil, and gradually spreading in breadth towards the long-boat. I call it smoothed, not that it was laid level; but because, though the swell continued, its surface was not roughened by the wrinkles, or smaller waves, before-mentioned; and none or very few white caps (or waves whose tops turn over in foam) appeared in that whole space, though to windward and leeward of it there were plenty; and a wherry, that came round the point under sail, in her way to Portsmouth, seemed to turn into that tract of choice, and to use it from end to end, as a piece of turnpike-road.

   2It may be of use to relate the circumstances of an experiment that does not succeed, since they may give hints of amendment in future trials: it is therefore I have been thus particular. I shall only add what I apprehend may have been the reason of our disappointment.

Differentiation Strategies

Assessment Guidance

1. Question 1 of 20 · Multiple Choice

   What is the central idea of paragraphs 2 and 3 of Passage 4 taken together?

   AAir can be pumped out of water, and the water soon takes in the same amount of air again BBecause air touches water directly, moving air can rub the surface into tiny wrinkles that start waves CWind is simply air in motion, which passes over the smooth surface of the water on every pond and lake DWater and air push each other away, so waves form along the line where the two of them meet

2. Question 2 of 20 · Multiple Choice

   Why does Franklin mention the air-pump in paragraph 2?

   ATo show that water takes in air, which supports his point that air and water are in direct contact BTo describe the tool that he used to make waves on the pond at Clapham before he dropped the oil in CTo explain that oil can be pumped onto rough water in a thin stream to calm it more quickly DTo prove that wind is made by machines such as pumps, and not only by changes in the weather

3. Question 3 of 20 · Multiple Choice

   What is the purpose of the bell example in paragraph 5?

   ATo show that Franklin studied church bells and their ropes as carefully as he studied waves BTo prove that bells and waves are made of the same kind of matter and so behave the same way CTo show how a small push, repeated many times, can build a very large motion, as the wind does with waves DTo warn readers that a heavy bell, once it is swinging at its full height, is far too strong to stop by hand

4. Question 4 of 20 · Multiple Choice

   Which sentence from Passage 4 states Franklin's conclusion about how oil calms a pond?

   A"It moves a little the oil indeed, which being between it and the water, serves it to slide with" B"continually increased in magnitude, rising higher and extending their bases, so as to include a vast mass of water in each wave" C"This prevention I would thus endeavour to explain." D"For the wind being thus prevented from raising the first wrinkles, that I call the elements of waves, cannot produce waves"

5. Question 5 of 20 · Multiple Choice

   Paragraph 5 says a swinging bell moves "with a force that cannot be resisted by the whole strength of the arm and body." Why can a short summary of Passage 4 leave this detail out?

   AIt is a detail inside a comparison, and a summary needs only the point of that comparison BIt is not true of real bells, and a careful summary always leaves out statements that are false CIt is Franklin's opinion about bells, and opinions never belong in any kind of summary DIt comes from a different text, so it counts as prior knowledge in a summary of Passage 4

6. Question 6 of 20 · Multiple Choice

   In paragraph 6, Franklin compares the oil on the water to

   Aa looking-glass lying flat on a table, which keeps a drop of oil in its place Ba sail on a ship, which catches the wind and pulls the whole ship across the open sea Ca heavy bell hanging still in a tower, which only moves when it is pushed Doil between the parts of a machine, which stops them from rubbing hard together

7. Question 7 of 20 · Multiple Choice

   Paragraph 5 says the small first-raised waves keep growing. Which words from paragraph 5 show that they grow because the wind keeps acting on them, not because the wind blows harder?

   A"A finger applied to a weighty suspended bell can at first move it but little" B"though the wind does not increase in strength" C"rising higher and extending their bases, so as to include a vast mass of water in each wave" D"which in its motion acts with great violence"

8. Question 8 of 20 · Multiple Choice

   A student's summary of Passage 4 includes these four sentences. Which one is an opinion?

   AFranklin says large waves carry a vast mass of water. BHe opens by saying he will explain how the calm is made. CHis bell comparison is the cleverest part of the letter. DHe says water that loses its air soon takes in more air.

9. Question 9 of 20 · Multiple Choice

   Which sentence in a summary of Passage 4 comes from prior knowledge rather than from the passage?

   AOil floats on water because it is less dense than water. BFranklin says water soon takes in air again after it is pumped out. CFranklin says large waves move with great violence. DFranklin compares the growing waves to a swinging bell.

10. Question 10 of 20 · Multiple Choice

    Which is the most accurate one-sentence summary of paragraph 4?

    AA small wave sinks right away and leaves the water all around it calm and still. BA stone dropped in a pool makes one wave, and after that the pool stays completely still. CWaves on ponds and lakes are caused mostly by stones and other objects falling into them. DAs a small wave sinks, it raises the water next to it, so waves spread outward in rings.

11. Question 11 of 20 · Multiple Choice

    Passage 4 contains a line with only "[...]" between paragraphs 5 and 6. What should a student writing a summary do about it?

    AGuess what the missing paragraph probably said and add it to the summary BTreat the mark as Franklin's own way of showing a pause in his thinking CSummarize only what is printed, because a paragraph has been left out there DSkip paragraph 6 as well, since it comes right after the gap in the passage

12. Question 12 of 20 · Multiple Choice

    Paragraph 6 begins, "Now I imagine that the wind..." How should an accurate summary report this idea?

    AAs a proven fact: "Oil makes the wind slide over the water." BAs Franklin's explanation: "Franklin thinks the wind slides over oiled water." CAs the student's own idea: "I think the wind slides over the water when there is oil." DIt should be left out, because Franklin is only imagining

13. Question 13 of 20 · Multiple Choice

    A student's summary says: "Franklin shows that oil can stop any wave." Why is this inaccurate?

    AFranklin says oil makes waves bigger and rougher, not smaller BFranklin never says that oil has any effect on waves at all CThe summary is much too short to be accurate about a passage as long as this one DPassage 4 is about waves the wind raises; it does not say oil stops every wave

14. Question 14 of 20 · Multiple Choice

    After reading Passage 5, a student adds this sentence to a summary of Passage 4: "The oil film is only a few billionths of a meter thick." Why should it be left out?

    AIt comes from another text, not from Passage 4, so here it counts as outside knowledge BIt is an opinion about Franklin's letter, and opinions do not belong in a summary CIt is false, because Franklin measured the oil film and found it much thicker than that DIt contradicts what Franklin says about the oil film in paragraph 6 of Passage 4

15. Question 15 of 20 · Short Answer

    State the central idea of all of Passage 4 in one sentence of your own. Then name two details that support it and cite their paragraphs.

    Show model answer

16. Question 16 of 20 · Short Answer

    Write a summary of Passage 4 in 3-4 sentences. Include no opinions and nothing that is not in the passage.

    Show model answer

17. Question 17 of 20 · Short Answer

    Here is a classmate's summary of Passage 4: "Franklin brilliantly explains waves. Waves are made by wind and by the moon's pull. He says wind rubs the water into wrinkles and oil lets the wind slide over. I think the bell part is confusing." Find the opinions and the prior knowledge, and rewrite the summary.

    Show model answer

18. Question 18 of 20 · Short Answer

    Passage 2 and Passage 5 both explain why a drop of oil spreads on water. What does each one conclude? Cite one phrase from each.

    Show model answer

19. Question 19 of 20 · Short Answer

    At Clapham (Passage 1), oil put on the leeward side of the pond did not work. How does paragraph 6 of Passage 4 help explain why the oil has to go on the windward side?

    Show model answer

20. Question 20 of 20 · Short Answer

    Explain the difference between a summary of Passage 4 and an opinion about it. Write one sentence of each.

    Show model answer

These standards connect to RST.6-8.2: prerequisites to review first, parallel standards at the same level, and next steps that build on it.

Standard text: Common Core State Standards for English Language Arts & Literacy. © Copyright 2010. National Governors Association Center for Best Practices and Council of Chief State School Officers. All rights reserved.