1.3 Small Group · Group 2
Second Challenge Form · Non-Routine Extension · Same Standard, New Problems
representation · tape diagram · Procedural Fluency · Real-World Applications
- You already can do this. So we go up a level, not up a number: find what is always true, show it a second way, and be ready to defend it with a reason instead of an answer.
- A pile of coins is too big to count one at a time. About how many coins are in the pile?
- I do not count every coin — I find a small stack I CAN count, about 10 coins.
- Then I estimate how many stacks like that are in the pile. I count about 15.
- 15 stacks of about 10 is 15 × 10 = 150, so my estimate is about 150 coins — reasoned, not random.
- One tram ride takes 12.5 minutes, so 10 rides take 12.5 × 10 = 125 minutes and 50 rides take 12.5 × 50 = 625 minutes.
- The tram needs 50 rides to move 4,000 passengers, and 625 minutes is 625 ÷ 60 hours — about 10.42 hours.
- A tape diagram of 4,000 cut into equal rides shows WHY we divide, and the table shows how minutes grow with rides.
- Now prove it: say why that move had to work at all — not just that it did.
- Sentence frame — convince a skeptic: "My method works because ___ . It would stop working if ___ ."
- representation (representación) — A picture, diagram, table, or equation that shows the mathematics in a situation.
- tape diagram (diagrama de cintas) — A rectangle cut into equal parts that helps you visualize how a total breaks apart.
- tool (herramienta) — Anything you choose to help you see relationships and solve a problem — a table, a diagram, a graph.
- ordered pair (par ordenado) — Two numbers that go together, like a time and a number of trips, that you can plot as a point.
- round trip (viaje de ida y vuelta) — A complete journey from the start, to the destination, and back to the start.
- Converting minutes to hours by moving the decimal point — 625 minutes is NOT 6.25 hours. An hour is 60 minutes, so divide by 60: 625 ÷ 60 ≈ 10.42 hours.
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1 MULTIPLE CHOICE
The 50 rides take 625 minutes. About how many HOURS is that?
- AAbout 10.42 hours
- BAbout 6.25 hours
- CAbout 62.5 hours
- DAbout 12.5 hours
✏️ Workspace & Solution Steps -
2 MULTIPLE CHOICE
How does the answer change for 2,000 passengers? Each ride carries 80 passengers and takes 12.5 minutes. How many MINUTES are needed?
- A312.5 minutes
- B31.25 minutes
- C3,125 minutes
- D300 minutes
✏️ Workspace & Solution Steps -
3 MULTIPLE CHOICE
One round trip takes 35 minutes. Using the table (35 → 1, 350 → 10, 525 → 15, 700 → 20), how many round trips does a tram car complete in 10 hours?
- A17 round trips
- B20 round trips
- C15 round trips
- D18 round trips
✏️ Workspace & Solution Steps
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4 OPEN RESPONSE
The lesson says we make strategic decisions about which tool to use. For the 10-hour round-trip question, would you choose a table of values, a coordinate plane, or an equation? Defend your choice.
✏️ Mathematical Justification & Response -
5 OPEN RESPONSE
Math is in YOUR world. Describe a real situation from your life that works like the tram problem — a total split into equal groups, or a time built from equal chunks — and show the math.
✏️ Mathematical Justification & Response -
6 ERROR ANALYSIS
Fix our table's thinking
- 1The problem:Apply — What Time Is It? The new year starts at midnight on January 1st. What time will it be 2,022 minutes after midnight?
- 2A classmate at our table answered:8:22 p.m. on January 1
Which step contains the error? Explain the mathematical misconception and write the correct calculation below.
✏️ Corrected Mathematical Work & Explanation
Writing Task: Justify why your mathematical solution is accurate and complete.