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Reading & writing · Grades 4–7

The strongest bridge?

Read once, answer together, and check your reasoning.

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The strongest bridge?

Three paper bridge designs are tested across equal gaps. Design A holds 18 counters, B holds 23 and C holds 20. Each design is tested only once. The class reports that B held the most counters in this trial, but avoids calling it the strongest design in every situation. Next, they plan repeated tests using fresh paper and identical counter placement.

Try it yourself

  1. How many more counters did B hold than A?

  2. Why does the class avoid a universal claim?

  3. Name two conditions they plan to control.

  4. Which statement is directly supported: B held most in this trial, or B is always strongest?

Check your understanding

Answers and marking notes
  1. 5

    23 − 18 = 5

  2. Each design was tested only once, and outcomes may vary with materials, construction and placement.

    Each design was tested only once, and outcomes may vary with materials, construction and placement.

  3. Fresh comparable paper and identical counter placement; equal gaps are also controlled.

    Fresh comparable paper and identical counter placement; equal gaps are also controlled.

  4. B held most in this trial.

    B held most in this trial.

Learning preview · teacher review required. Grade bands are approximate, not official curriculum alignment.