Question Your e-scooter battery shows 88% when you leave campus at 3:10. At 3:40 it shows 61%. Something clearly moved — but "it went down" is too vague for calculus. Did it drop steadily, or mostly on that last hill? Over forty minutes, or only while the motor was under load? Change has a size, a direction, and a window of input — usually time.
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Describe change with size, direction, and an input interval Name independent vs dependent variables in a scenario Separate total (net) change from how fast change happens inside the interval Sketch a simple quantity-vs-time picture and read steep vs flat segments
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E-scooter battery 3:10 → 88% 3:40 → 61% Café wait time Open: 4 min +1 hr: 11 min Size? Direction? Over what input window?
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