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: Operations & Algebraic Thinking
CCSS.Math.Content.4.OA.A.1 Interpret a multiplication equation as a comparison, e.g., interpret 35 = 5 × 7 as a statement that 35 is 5 times as many as 7 and 7 times as many as 5. Represent verbal statements of multiplicative comparisons as multiplication equations.
CCSS.Math.Content.4.OA.A.2 Multiply or divide to solve word problems involving multiplicative comparison, e.g., by using drawings and equations with a symbol for the unknown number to represent the problem, distinguishing multiplicative comparison from additive comparison.1
CCSS.Math.Content.4.OA.A.3 Solve multistep word problems posed with whole numbers and having whole-number answers using the four operations, including problems in which remainders must be interpreted. Represent these problems using equations with a letter standing for the unknown quantity. Assess the reasonableness of answers using mental computation and estimation strategies including rounding.

2. If a Siberian tiger was on one end of a seesaw, how many adults would you need on the other end to balance him out?
© Hans Kuczka/Aurora Photos
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. If a Siberian tiger was on one end of a seesaw, how many adults would you need on the other end to balance him out?
The male Siberian tiger can weigh in at more than 400 pounds and measures longer than 6 feet from nose to tail. So we consider ourselves lucky that most of us will only ever see these magnificent predators from the safety of zoos, like this one in Antwerp, Belgium.
In their natural habitat, the mountainous Sikhote Alin region, Siberian tigers are endangered. Poaching is one of the primary problems, but habitat loss has also been a factor. Because the larger range of the tigers includes portions of China, the Chinese and Russian governments have made joint efforts recently to work on stronger protection efforts to preserve the tigers.
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. If a Siberian tiger was on one end of a seesaw, how many adults would you need on the other end to balance him out? 1
Thinking
How could you translate this word problem into a mathematical equation? What operation(s) will you need to use to solve for this? 2
How could you represent this question visually? Draw a picture that shows what this equation is asking. 3
Web Search
How much does the average adult weigh? What does it mean that this is the average? 4
How much does the average Siberian tiger weigh? What does it mean that this is the average? 5
Do you think this mathematical equation is one where there could be remainders? What would it mean (in words) if there were remainders?
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. If a Siberian tiger was on one end of a seesaw, how many adults would you need on the other end to balance him out? 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. If a Siberian tiger was on one end of a seesaw, how many adults would you need on the other end to balance him out? 1
Thinking
How could you translate this word problem into a mathematical equation? What operation(s) will you need to use to solve for this? 2
How could you represent this question visually? Draw a picture that shows what this equation is asking. 3
Web Search
How much does the average adult weigh? What does it mean that this is the average? 4
How much does the average Siberian tiger weigh? What does it mean that this is the average? 5
Do you think this mathematical equation is one where there could be remainders? What would it mean (in words) if there were remainders?
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. If a Siberian tiger was on one end of a seesaw, how many adults would you need on the other end to balance him out? 1
Thinking
How could you translate this word problem into a mathematical equation? What operation(s) will you need to use to solve for this?
This is a chance for students to begin thinking conceptually about how to translate this word problem into an equation. If it helps, they can think about the mathematical formula itself like the seesaw being balanced out. They can start with something very basic, for example:
Weight of tiger = Weight of x number of people
Students should think about what the unknown is in the problem and represent this with “x”: how many people are equal to the weight of the tiger. In order to do so, they could use addition to add up the weights of different people until it equals the weight of the tiger. If we assume the people are all the same weight (they’re all averaged- sized adults), they could divide the weight of the tiger by this number to see what “x” is equal to. In other words, they should determine that the operations of multiplication and division will be the most helpful.

8. If a Siberian tiger was on one end of a seesaw, how many adults would you need on the other end to balance him out? 2
Thinking
How could you represent this question visually? Draw a picture that shows what this equation is asking.
This is an opportunity for students to practice thinking conceptually about what this word problem is asking for. They can use symbols or drawings to stand in for various parts of the equation. Answers will vary. For example:
T = P (This would be assuming 1 person is equal to the weight of 1 tiger)
T = P + P (This would be assuming 2 people are equal to the weight of 2 tigers)
T = P + P + P (This would be assuming 3 people are equal to the weight of 3 tigers)
If T = tiger and P = people

9. If a Siberian tiger was on one end of a seesaw, how many adults would you need on the other end to balance him out? 3
Web Search
How much does the average adult weigh? What does it mean that this is the average?
(Possible queries: “for kids, what is an average?”, “how much does the average adult weigh?”).
From
The weight of an average adult in North America is pounds.
And from
An average is a calculated "central" value of a set of numbers. To calculate: add up all the numbers, then divide by how many numbers there are. Example: what is the average of 2, 7 and 9? Add the numbers: = 18 Divide by how many numbers (i.e. we added 3 numbers): 18 ÷ 3 = 6 So the average is 6.
Students should understand from this definition that the average weight of an adult in North America is (hypothetically) calculated by taking the weights of all of the adults in North America and dividing by the number of people there are. Therefore pounds is not the largest weight or smallest weight, but the weight in the middle of all of them. It also does not mean that most people weigh pounds—an average is different from the most common number.

10. If a Siberian tiger was on one end of a seesaw, how many adults would you need on the other end to balance him out? 4
Web Search
How much does the average Siberian tiger weigh? What does it mean that this is the average?
(Possible queries: “for kids, what is an average?”, “how much does the average Siberian tiger weigh?”).
From
The average weight of the male Siberian tiger is 389 pounds (260 pounds for females).
And from
An average is a calculated "central" value of a set of numbers. To calculate: add up all the numbers, then divide by how many numbers there are. Example: what is the average of 2, 7 and 9? Add the numbers: = 18 Divide by how many numbers (i.e. we added 3 numbers): 18 ÷ 3 = 6
Students should understand from this definition that the average weight of a Siberian tiger is (hypothetically) calculated by taking the weights of all of the male or female tigers and dividing by the number of male or female tigers there are. This does not mean that most tigers weigh exactly this amount—an average is different from the most common number. Moving forwards, students can choose whether to use the male or female average to solve the problem, or can find the average of the two averages by following the example given and adding 389 pounds and 260 pounds and dividing by 2. (389 / 260 = 324.5).

11. If a Siberian tiger was on one end of a seesaw, how many adults would you need on the other end to balance him out? 5
Thinking
Do you think this mathematical equation is one where there could be remainders? What would it mean (in words) if there were remainders?
Students should consider what a remainder would represent in this equation. They should think about how it might be unlikely to find people who exactly balanced out the Siberian tiger on the seesaw, especially considering they are using the average weight of adults to find the number of people needed to do so. It would probably be difficult to find people who are exactly average-sized, and even if they did, whether average-sized adults would balance out the tiger perfectly evenly. Because of this, there may be remainders when solving for the number of people needed. Students should also consider, however, that because their answer will be in units of “people”, a remainder would represent part of a person, which wouldn’t make much sense. Students should conclude that because of this, an estimation or rounding would be best. They can state their answer with “around x number of average-sized people”, rather than giving a precise remainder that represents part of a person.

12. If a Siberian tiger was on one end of a seesaw, how many adults would you need on the other end to balance him out?
This slide is a chance to summarize the information from the previous slides to build your final answer to the question. Answers may vary depending on the averages students found and whether they are using the average weight of male or female tigers and humans. For example:
Average weight of Siberian tiger = pounds
Average weight of North American person = pounds
324.5 = x ?
? = 1.824
In other words, around 2 average-sized adults would be needed to balance out the weight of a Siberian tiger on a seesaw.