1fa58982-2978-42da-8576-ff21c53c5868.html

<h3>Warm Up (5 minutes)</h3>
<p>In this warm up, students compare the changes in output (temperature) over two intervals of input (time). The temperature in one interval changes by a greater amount than in the other interval, but in the latter, temperature changes more rapidly.</p>
<p>Thinking about what it means for temperature to drop &ldquo;faster&rdquo; activates the idea of rates of change and prepares for the work later in the lesson.</p>
<h4>Launch</h4>
<p>Display the task for all to see. Give students 2 minutes of quiet time to work the question and then follow with a whole-class discussion.</p>
<h4>Student Activity</h4>
<p>Here are the recorded temperatures at three different times on a winter evening.</p>
<table class="os-raise-horizontaltable">
  <thead></thead>
  <tbody>
    <tr>
      <th scope="row">
        time
      </th>
      <td>
        4 p.m.
      </td>
      <td>
        6 p.m.
      </td>
      <td>
        10 p.m.
      </td>
    </tr>
    <tr>
      <th scope="row">
        temperature
      </th>
      <td>
        25&deg;F
      </td>
      <td>
        17&deg;F
      </td>
      <td>
        8&deg;F
      </td>
    </tr>
  </tbody>
</table>
<br>
<ul>
  <li>Tyler says the temperature dropped faster between 4 p.m. and 6 p.m.</li>
  <li>Mai says the temperature dropped faster between 6 p.m. and 10 p.m.</li>
</ul>
<p>Who do you agree with? Be prepared to show your reasoning.</p>
<p><strong>Answer: </strong></p>
<p>Compare your answer:</p>
<ul>
  <li>I agree with Mai. The temperature dropped 8&deg;F between 4 p.m. and 6 p.m., but it fell 9&deg;F between 6 p.m. and 10 p.m.</li>
  <li>I agree with Tyler. The temperature dropped 4&deg;F per hour between 4 p.m. and 6 p.m. It fell less than 4&deg;F per hour in the evening.</li>
</ul>
<h4>Anticipated Misconceptions </h4>
<p>Some students may ask for a clarification as to what is meant by &ldquo;faster&rdquo; in this situation. Acknowledge that thinking about its meaning in context is a great way to approach the task. Encourage these students to interpret the word based on their understanding of the given information.</p>
<h4>Activity Synthesis </h4>
<p>Poll the class on whether they agree with Mai or with Tyler. Select 1&ndash;2 students from each group to explain their reasoning. As they explain, record and display their thinking for all to see. After both groups have had a chance to present, ask if anyone changed their mind because of the explanation they heard. If so, invite them to share their reasons.</p>
<p>It is not necessary to resolve the question at this point. Students will continue thinking about this question in the next activity.</p>