1. Estimating Length and Selecting Tools Unit of Study 8: Customary Measure Length Global Concept Guide: 2 of 3

2. Content Development

3. In all measurement activities, emphasize the use of approximate language. The desk is about 4 feet long. The chair is a little less than 16 inches high. Many measurements do not come out even. Older children will begin to search for smaller units or will use fractional units to try to measure exactly. Here is an opportunity to develop the idea that all measurements include some error. Each smaller unit or subdivision does produce a greater degree of precision. (Van de Walle, 2006) For more information on measurement watch this podcast.podcast

4. Day 1  Essential Question: How do you estimate the lengths of objects in inches and feet?  Possible Engage: Cotton Ball Toss (focuses on estimation in inches). Make sure students turn in recording sheets as evidence of learning.Cotton Ball Toss  Have students get in pairs/groups and give each pair/group a set of materials (cotton balls, ruler, recording sheet, and tape to place for the starting line).  Each student places their feet at the starting line and takes one turn tossing the cotton ball.  After each toss, the student who tosses the cotton ball estimates the distance in inches and records their estimate on the recording sheet.  After recording their estimate, the student uses the ruler to measure the distance from the starting line to the cotton ball to determine the distance it traveled. The actual measurement is recorded on the recording sheet.  Students then record the difference between their estimate and the actual measurement as their “score.” The student with the lowest “score” wins.  Facilitate discussion about reasonable estimates.  Some questions to ask to facilitate discussion include:  How did your estimate compare to your actual toss?  Was your estimate a reasonable estimate? Explain.  If you were to toss again, how would your estimate change?  GO Math Lesson 8.3 students can either complete Share and Show on p. 398 OR On Your Own p.399.  Problem Solving p. 400 is excellent application of estimation of inches.  At the end of Day 1, students will be able to make reasonable estimates in a variety of situations in inches.

5. Day 2  Essential Question: How do you estimate the lengths of objects in feet?  Students can continue to build understanding of estimation through the Long Jump activity (Focuses on estimation of feet). Make sure students turn in recording sheets as evidence of learning.Long Jump  Place students in pairs or groups.  Explain to students that they are going to measure their jumps from a starting position.  Student will select an appropriate unit for measuring their jump.  Student will then make an estimate as to how far he/she can jump.  Student will record their estimate on a recording sheet.  Student will then start at the starting point and jump as far as they can.  Student will record where they landed and then measure the exact length of their jump.  Student will then find the distance between their estimate and the actual measurement.  Student repeats the jump 5 times.  Continue to facilitate discussion about reasonable estimates. Some questions could include:  How did your estimate change from the first jump to the last jump?  Did you change the tool you selected to measure your jumps?  How did your estimate compare to your actual jump?  Was your estimate reasonable? Explain.  If you were to jump again, how would your estimate change? Estimation in FeetEstimation in Feet can be used on Day 1 to help solidify understanding of estimation. Problem Solving p. 416 is excellent application of estimation of feet.  Possible daily journal question.daily journal question.  At the end of Day 2, students will be able to make reasonable estimates in a variety of situations in feet.

6. Day 3  Essential Question: How do you select an appropriate tool to use when measuring?  Students need to learn, through hands-on experiences, that an inch ruler is a more appropriate tool to use to measure small objects while yardsticks and measuring tapes are more appropriate for larger objects. Additionally, students build understanding that a measuring tape is more appropriate to measure a curved surface.  Possible Engage: Provide students with an object that is curved (ex. ball, globe, cup, water bottle, etc.)  Give students a yard stick and ruler. Allow students the opportunity to measure the curved object with the yard stick or ruler. Students will most likely become frustrated at trying to measure a curved object with a straight edge. Facilitate discussion as to why it is difficult to measure the curved object. Ask students what could make it easier to measure the object. Students may say string or another object that can be wrapped around the curved surface.  After students used the ruler/yardstick, provide students with a measuring tape and ask how they might use this tool to measure the curved object.  Facilitate a discussion about how the measuring tape was easier to use, provided a more efficient measurement and was a better tool for the task.  After students have had the hands on experience, have them complete the task Tony’s Tools. In this task, students match the appropriate tool to measure the object.Tony’s Tools  Go Math Lesson 8.8 could be used to help students practice selecting the appropriate tool for the measuring situation.  By the end of Day 3, students will be able to select the tool that is most appropriate for measuring a designated object.

7. Enrich/Reteach/Intervention  Reteach  RtI Tier 2 TE pg. 413B - estimation  Reteach 8.8 Student Page R84 –choosing a tool  Animated Go Math Model: Estimate and Measure Inches Animated Go Math Model  Enrich  Enrich TE pg. 417B – students select objects around the school, select a tool and record measurement  Go Deeper TE pg. 419 – students measure the same object with three different tools and determine which is most effective  Enrich E79