1. Teacher Guide
This lesson is designed to teach kids to ask a critical thinking question that you can’t just put into a search box to solve. To do that, we encourage them with smaller questions that search can help them answer. Make sure that you read the notes for each slide: they not only give you teaching tips but also provide answers and hints so you can help the kids if they are having trouble.
Remember, you can always send feedback to the Bing in the Classroom team at You can learn more about the program at bing.com/classroom and follow the daily lessons on our Partners In Learning site.
Want to extend today’s lesson? Consider using Skype in the Classroom to arrange for your class to chat with another class in today’s location. And if you are using Windows 8, you can also use the Bing apps to learn more about this location and topic; the Travel and News apps in particular make great teaching tools.
Nell Bang-Jensen is a teacher and theater artist living in Philadelphia, PA. Her passion for arts education has led her to a variety of roles including developing curriculum for Philadelphia Young Playwrights and teaching at numerous theaters and schools around the city. She works with playwrights from ages four to ninety on developing new work and is especially interested in alternative literacies and theater for social change. A graduate of Swarthmore College, she currently works in the Artistic Department of the Wilma Theater and, in addition to teaching, is a freelance actor and dramaturg. In 2011, Nell was named a Thomas J. Watson Fellow and spent her fellowship year traveling to seven countries studying how people get their names.
This lesson is designed to teach the Common Core State Standard: Measurement & Data
CCSS.Math.Content.2.MD.B.5 Use addition and subtraction within 100 to solve word problems involving lengths that are given in the same units, e.g., by using drawings (such as drawings of rulers) and equations with a symbol for the unknown number to represent the problem.
CCSS.Math.Content.2.MD.D.9 Generate measurement data by measuring lengths of several objects to the nearest whole unit, or by making repeated measurements of the same object. Show the measurements by making a line plot, where the horizontal scale is marked off in whole-number units.

2. The Great Gray Owl and Eurasian Eagle-Owl are the largest species of owls on Earth. How could you compare their weights and wingspans to determine which, on average, is the bigger owl?
© J. Peltomaeki/age fotostock
Having this up as kids come in is a great settle down activity. You can start class by asking them for thoughts about the picture or about ideas on how they could solve the question of the day.

3. The Great Gray Owl and Eurasian Eagle-Owl are the largest species of owls on Earth. How could you compare their weights and wingspans to determine which, on average, is the bigger owl?
Researchers believe the great gray owl is the largest species of owl on Earth, though it’s out-weighed by the Eurasian eagle-owl. As it happens, great size coupled with relatively low weight is key to the great gray owl’s success as a hunter. Females average less than three pounds, males a little more than two. That leaves room for profuse, noise-reducing plumage, making it essentially silent in flight. With a wingspan as wide as 60 inches, they’re well-adapted to cruise the upper territory of the Northern Hemisphere, searching for small rodents and voles.
Depending on time, you can either have students read this silently to themselves, have one of them read out loud, or read it out loud yourself.

4. The Great Gray Owl and Eurasian Eagle-Owl are the largest species of owls on Earth. How could you compare their weights and wingspans to determine which, on average, is the bigger owl? 1
Web Search
What is an average? Why is it helpful to use averages to compare the size of these two species of owls? 2
Web Search/Thinking
What units do you think will be helpful for comparing weights and wingspans? Why is it helpful to use the same units when making comparisons? 3
What is the average wingspan of the Great Gray Owl? What is the average wingspan of the Eurasian Eagle-Owl? What does this tell us? 4
What is the average weight of the Great Gray Owl? What is the average weight of the Eurasian Eagle-Owl? What does this tell us? 5
Why might it be hard to determine which owl is “bigger” without breaking down their sizes to wingspan and weight?
There are a couple of ways to use this slide, depending on how much technology you have in your classroom. You can have students find answers on their own, divide them into teams to have them do all the questions competitively, or have each team find the answer to a different question and then come back together. If you’re doing teams, it is often wise to assign them roles (one person typing, one person who is in charge of sharing back the answer, etc.)

5. The Great Gray Owl and Eurasian Eagle-Owl are the largest species of owls on Earth. How could you compare their weights and wingspans to determine which, on average, is the bigger owl? 5
Minutes
You can adjust this based on how much time you want to give kids. If a group isn’t able to answer in 5 minutes, you can give them the opportunity to update at the end of class or extend time.

6. The Great Gray Owl and Eurasian Eagle-Owl are the largest species of owls on Earth. How could you compare their weights and wingspans to determine which, on average, is the bigger owl? 1
Web Search
What is an average? Why is it helpful to use averages to compare the size of these two species of owls? 2
Web Search/Thinking
What units do you think will be helpful for comparing weights and wingspans? Why is it helpful to use the same units when making comparisons? 3
What is the average wingspan of the Great Gray Owl? What is the average wingspan of the Eurasian Eagle-Owl? What does this tell us? 4
What is the average weight of the Great Gray Owl? What is the average weight of the Eurasian Eagle-Owl? What does this tell us? 5
Why might it be hard to determine which owl is “bigger” without breaking down their sizes to wingspan and weight?
You can ask the students verbally or let one of them come up and insert the answer or show how they got it. This way, you also have a record that you can keep as a class and share with parents, others.

7. The Great Gray Owl and Eurasian Eagle-Owl are the largest species of owls on Earth. How could you compare their weights and wingspans to determine which, on average, is the bigger owl? 1
Web Search
What is an average? Why is it helpful to use averages to compare the size of these two species of owls?
(Possible queries: “for kids, what is an average”, “for kids, what does the ‘average’ of something mean?”).
From
An average is a number that is calculated by adding quantities together and then dividing the total by the number of quantities. Also defined as a level that is typical of a group, class, or series : a middle point between extremes.
Students should understand from this description (or similar ones) that averages look at what is common within a whole group, mathematically. Students should recognize that using the average to compare the sizes of owls is the most helpful way to compare them. If you just compared two owls, one of each kind, it would only give you information about the two individuals, not the species as a whole. If this were the case, one may be an especially large owl for its size, and one may be an especially small owl for its size, giving you an inaccurate sense of which is bigger. The average looks at more data as a whole and will give you a better overall picture.

8. The Great Gray Owl and Eurasian Eagle-Owl are the largest species of owls on Earth. How could you compare their weights and wingspans to determine which, on average, is the bigger owl? 2
Web Search/Thinking
What units do you think will be helpful for comparing weights and wingspans? Why is it helpful to use the same units when making comparisons?
(Possible queries: “wingspan of owls”, “how much do owls weigh?”).
Students should conduct search queries to get a sense of what units these measurements are given in. They will find that weights are most often described in pounds or ounces, and wingspans are usually described in feet, inches, or centimeters. Students should then think about why it’s important to use the same units when making comparisons. It may help for them to think of an example where the same units are not being used; for example, if one owl was said to have the wingspan of 1 foot, and the other owl was said to have a wingspan of 16 inches. Ask them to think about why this would make it harder to compare them than if the wingspan of both owls were described in feet or inches.

9. The Great Gray Owl and Eurasian Eagle-Owl are the largest species of owls on Earth. How could you compare their weights and wingspans to determine which, on average, is the bigger owl? 3
Web Search
What is the average wingspan of the Great Gray Owl? What is the average wingspan of the Eurasian Eagle-Owl? What does this tell us?
(Possible queries: “what is the average wingspan of the Great Gray Owl?”, “what is the average wingspan of the Eurasian Eagle-Owl?”).
From and from
The average wingspan of the Great Gray Owl is in. The Eurasian Eagle-Owl has an average wingspan of 63 – 74 inches.
Students should note from this information that the Eurasian Eagle-Owl has a larger wingspan, on average. If we were comparing wingspans only, the Eurasian Eagle-Owl would be the (slightly) bigger owl.
Answers may vary slightly, depending on the source.

10. The Great Gray Owl and Eurasian Eagle-Owl are the largest species of owls on Earth. How could you compare their weights and wingspans to determine which, on average, is the bigger owl? 4
Web Search
What is the average weight of the Great Gray Owl? What is the average weight of the Eurasian Eagle-Owl? What does this tell us?
(Possible queries: “what is the average weight of the Great Gray owl?”, “what is the average weight of the Eurasian Eagle-Owl?”).
From and
Great Gray Owl: The adult weight ranges from 580 to 1,900 g (1.28 to 4.19 lb), averaging 1,290 g (2.84 lb) for females and 1,000 g (2.2 lb) for males.
Eurasian Eagle-Owl: The weight of the females is 1.75 – 4.2 kg (3.9 – 9.3 lb). The males weigh about 1.5 – 3 kg (3.3 – 6.6 lb).
Students should note from this information that the Eurasian Eagle-Owl weighs more, on average. If we were comparing weights only, the Eurasian Eagle-Owl would be the bigger owl.

11. The Great Gray Owl and Eurasian Eagle-Owl are the largest species of owls on Earth. How could you compare their weights and wingspans to determine which, on average, is the bigger owl? 5
Web Search/Thinking
Why might it be hard to determine which owl is “bigger” without breaking down their sizes to wingspan and weight?
Students should think about why the term “bigger” may be too broad to define scientifically. It helps to break down the owls’ sizes into different parts. They might think about how one species of owl might be heavier, but the other might have a wider wingspan. In this case, it would be hard to say which is “bigger”—it depends on what kinds of measurements you’re using. This should serve as a lesson as the importance of units and specific data measurements when comparing two things.

12. The Great Gray Owl and Eurasian Eagle-Owl are the largest species of owls on Earth. How could you compare their weights and wingspans to determine which, on average, is the bigger owl?
This slide is a chance to summarize the information from the previous slides to build your final answer to the question. After gathering this information, students should determine that on average, the Eurasian Eagle-Owl is the bigger owl in terms of both weight and wingspan. They might note, however, that the Great Gray Owl comes very close to it in wingspan, though is much lighter. This means we know that for its size, the Great Gray Owl does not weigh a lot at all, which, as the image description points out, contributes to its ability as a hunter.