Five warm-ups for grades 9–12. Each takes three to five minutes. Answers and teacher notes are in the collapsed box under each prompt.
ELA
Parallel structure means putting items in a list or comparison in the same grammatical form: all nouns, all verbs in the same tense, all infinitives, and so on. Faulty parallelism makes a sentence sound lopsided. Rewrite each sentence so its parts are parallel, and name the form you chose.
- This weekend I plan to rake the leaves, carving a pumpkin, and to finish my essay.
- The coach told us to arrive early, that we should bring water, and stretching before practice.
- She is known for her honesty, her patience, and being creative.
- The new laptop is faster than the old one, and it is more lightweight, plus the battery lasts longer.
- Not only did the team win the championship, but also a franchise record was set.
Answer and teacher notes
1. “This weekend I plan to rake the leaves, carve a pumpkin, and finish my essay.” (Base verbs after one to.)
2. “The coach told us to arrive early, bring water, and stretch before practice.” (Infinitive phrases.)
3. “She is known for her honesty, her patience, and her creativity.” (Nouns.)
4. “The new laptop is faster, lighter, and longer-lasting than the old one.” (Comparative adjectives.)
5. “The team not only won the championship but also set a franchise record.” (Verb phrases after each half of the correlative pair; also fixes the shift to passive voice.)
Quick test: read the sentence starting with the shared word, then each item alone (“plan to rake… plan to carving…”). The one that sounds wrong is the broken one. Correlative pairs (not only… but also, either… or, both… and) need the same form after each part. Other answers can be correct if they’re consistent, for example “raking, carving, and finishing” in #1. Extension: find a famous speech that uses parallel structure and explain why repetition of form makes it memorable.
Math
Carving on Mount Rushmore in South Dakota began in October 1927 and ended in October 1941, 85 years ago this month. According to Britannica, each of the four presidents’ heads is about 60 feet tall, and about 450,000 tons of rock were removed during roughly six and a half years of actual carving. (a) Assume a typical adult head is about 9 inches from chin to crown. What is the scale factor of the sculpture? (b) At that scale, how tall would a 5-foot-9-inch person be, in feet? (c) If a solid statue were scaled up by this factor, by what factor would its surface area grow? Its volume and weight? (d) About how many tons of rock were removed per year of carving?
Answer and teacher notes
(a) 60 ft = 720 in; 720 ÷ 9 = 80. The sculpture is about 80 times life size.
(b) 5 ft 9 in = 69 in; 69 × 80 = 5,520 in ÷ 12 = 460 feet.
(c) Area scales by k² = 80² = 6,400; volume and weight by k³ = 80³ = 512,000.
(d) 450,000 ÷ 6.5 ≈ 69,000 tons per year (about 69,231).
Check (c) with a simple cube: double the sides of a 1 × 1 × 1 cube and the surface area goes from 6 to 24 (×4 = 2²) and volume from 1 to 8 (×8 = 2³). ✓ This “square-cube law” is why giant animals in movies couldn’t exist: weight grows much faster than the bone cross-sections that support it. The 9-inch head is a modeling assumption, not a measured fact, so students may get slightly different scale factors. Britannica also notes the project cost nearly $1 million; extension: about how much was that per ton of rock removed? (1,000,000 ÷ 450,000 ≈ $2.22 per ton, in 1930s dollars.) Common mistake: forgetting to convert feet to inches before dividing.
Source: Britannica: Mount Rushmore National Memorial (dates, head height, rock removed, carving time, and cost)
Science
When you bend a glow stick, a small inner container breaks, and two separate chemicals mix and react, releasing energy as light. This is chemiluminescence. In an American Chemical Society classroom demonstration, a glow stick placed in hot water glows brighter than one in cold water, and the cold one glows dimmer, which is why storing a glow stick in the freezer makes it last longer. (a) Explain, in terms of molecules, why the warm glow stick is brighter. (b) Why does freezing an activated glow stick make it last longer? (c) A common rule of thumb is that many reaction rates roughly double for every 10 °C rise. Suppose a glow stick lasts 8 hours at 20 °C. Estimate how long it would last at 0 °C and at 40 °C, assuming the total amount of light stays the same. (d) Is the rule of thumb a law of nature? What could make your estimate wrong?
Answer and teacher notes
(a) Heating raises the average kinetic energy of the molecules, so more of them collide, and more collisions have enough energy to react (to get over the activation energy). More reactions per second release more light per second: a brighter glow. (b) Cold slows the molecules, so fewer effective collisions happen each second. The same supply of reactants gets used up more slowly, spreading the light over a longer time. (c) 0 °C is 20 degrees colder: rate ÷ 2 ÷ 2 = ¼, so about 8 × 4 = 32 hours. 40 °C is 20 degrees warmer: rate × 4, so about 8 ÷ 4 = 2 hours. (d) No. It’s a rough approximation; the actual factor depends on the reaction’s activation energy and changes with temperature. Light output also isn’t perfectly constant over time, and very hot or cold conditions could affect the plastic, the mixing, or side reactions.
Note that the 8-hour lifetime in (c) is a made-up example for the calculation. Unlike a flame, chemiluminescence releases most of its energy as light rather than heat, so a glow stick stays cool. Connection: fireflies use a related light-making reaction (bioluminescence) controlled by enzymes. Extension: design a fair test of the glow-stick claim. What would you keep the same, what would you change, and how would you measure brightness?
Source: American Chemical Society: Middle School Chemistry, Chapter 6, Lesson 4 (Temperature and the Rate of a Chemical Reaction) (glow-stick demonstration and kinetic-energy explanation)
Social Studies
John Adams was born on October 30, 1735, in Braintree, Massachusetts. He served as the first vice president (1789–1797) and the second president (1797–1801). In 1800, the federal government moved from Philadelphia to the new city of Washington, and on November 1, 1800, Adams became the first president to move into the President’s House, now called the White House. Its cornerstone had been laid on October 13, 1792, and the building was still unfinished. The next night, Adams wrote to his wife, Abigail, hoping that “none but Honest and Wise Men ever rule under this Roof.” When Abigail arrived, she wrote, “There is not a single apartment finished.” (a) How old was Adams when he moved in? How many years ago will that be this Sunday? (b) About how long passed between the cornerstone and Adams’s arrival? (c) Why might it matter to move the government into its new capital on schedule, even before the buildings were done? (d) Adams wrote a wish, not a rule. What qualities does he name, and why might a leader write a hope like this for future leaders?
Answer and teacher notes
(a) He had turned 65 two days earlier (1800 − 1735 = 65, and his birthday is October 30). This Sunday is 2026 − 1800 = 226 years since he moved in. (b) October 13, 1792, to November 1, 1800: 8 years and 19 days, a little over 8 years. (c) Answers will vary: showing the new national government was stable and kept its commitments; making the new capital real in people’s minds; establishing that the government belonged to the whole country, not one existing city.
(d) Honesty and wisdom. Answers will vary: a written hope sets an expectation and a standard for later leaders to measure themselves against; it shows humility about the office; it treats the house as belonging to the nation rather than to one person. Britannica adds that Abigail used the unfinished East Room to dry laundry, a good detail for discussing how different early government was from today. Keep discussion historical and avoid comparisons to current officeholders. Extension: what does an unfinished building at move-in suggest about the challenges of building a new capital from scratch?
Sources: Britannica: John Adams summary (birth date and place, offices); Britannica: White House (cornerstone, 1800 move, November 1 arrival, Adams’s and Abigail’s words, East Room)
Current Events
On Wednesday, October 28, the Milwaukee Brewers beat the Tampa Bay Rays 4–1 in Game 5 to win the 2026 World Series, four games to one. It is the first World Series title in Brewers franchise history. The game-by-game scores (Brewers first): Game 1, 3–2; Game 2, 5–4; Game 3, 10–1; Game 4, 3–4 in 12 innings; Game 5, 4–1. In the regular season, the Brewers went 103–59 (a franchise record and the best in the majors) and the Rays went 98–64. (a) Find each team’s total runs and the run differential for the series. How much of the Brewers’ margin came from one game? (b) Find each team’s regular-season winning percentage. (c) Suppose the Brewers had a 0.55 chance of winning any single game, independent of the others. What is the probability they win the series in exactly five games? (d) Three of the five games were decided by one run. Does a 25–12 run total make the series look more lopsided than it was? Explain.
Answer and teacher notes
(a) Brewers: 3 + 5 + 10 + 3 + 4 = 25. Rays: 2 + 4 + 1 + 4 + 1 = 12. Differential: +13. Game 3 alone was +9, so 9 of the 13 runs (about 69%) of the margin came from one game; in the other four games combined, it was 15–11. (b) Brewers: 103 ÷ 162 ≈ .636. Rays: 98 ÷ 162 ≈ .605. (c) To win in exactly five, the Brewers must win 3 of the first 4 games and then Game 5: C(4,3) × 0.55³ × 0.45 × 0.55 = 4 × 0.55⁴ × 0.45 ≈ 4 × 0.0915 × 0.45 ≈ 0.165, about 16.5%.
(d) Answers will vary: yes, one blowout inflates the total; most games were very close, and one went 12 innings. Totals and averages can be skewed by an outlier, so the game-by-game data tells a fuller story. Teacher check for (c): with p = 0.55, the chance of winning the series in any number of games (4–7) is about 0.61, which shows how a modest per-game edge only slightly raises the chance of winning a best-of-seven series. MLB.com notes that the Brewers’ last World Series appearance was in 1982, and that just four franchises (the Mariners, Padres, Rays, and Rockies) have now never won the title. The 0.55 probability is a modeling assumption, not a published figure.
Sources: MLB.com: Brewers Beat Rays in Game 5 to Win First World Series in Franchise History (Game 5, first title, 103 wins, 1982, remaining franchises); Baseball-Reference: 2026 World Series (game-by-game scores and totals); Wikipedia: 2026 MLB Season (regular-season records)
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