Directions: The traditional method for calculating a dog's age in dog years is to multiply its age in human years by 7. The chart below describes a different method some veterinarians use to estimate a dog's age based on its size. Size Small Medium Large Giant Weight 20 pounds or less 21‒50 pounds 51‒90 pounds more than 90 pounds Age at 2 in Human Years 23 dog years 24 dog years 22 dog years 20 dog years Age Increase Each Year After 2 in Human Years 4 dog years 5 dog years 6 dog years 7 dog years
1. Choose a dog breed in each size category. You can use the dog breed charts on the following page or do research to choose a different breed. 2. Complete a table to show the dog year equivalent for each breed from 2–5 human years. 3. Let x equal the age, in human years, for a dog that is 2 years old or older. For each of your chosen breeds, write an expression to model its age in dog years. [Hint: Use (x 2) in each expression.] 4. Choose what you consider to be a really old, but realistic, age for people. 5. For each expression you write, plug in the value you chose in step 4—an old age for a human—for x. Set each expression equal to A. 6. Solve each equation, and explain what the solution means. Add the old-age values to your table. 7. Use your solutions to develop a convincing argument for why the method described in the chart is better than the traditional method. 8. You may wish to do research to find the average lifespan for each dog breed and use those facts in your argument. Use your table, equations, solutions, and arguments to create your debate presentation. Your presentation can be written, but you could also use slide presentation software or create a video of yourself giving the presentation. Your completed presentation will be submitted as your portfolio assessment.
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Small Dogs (20 lbs or less)
Medium Dogs (21‒50 lbs)
Large Dogs (51‒90 lbs)
Giant Dogs (more than 90 lbs)
border terrier Cavalier King Charles spaniel Chihuahua dachshund Lhasa apso Maltese miniature schnauzer Pekingese pug toy and miniature poodle Yorkshire terrier
cocker spaniel wheaten terrier border collie English springer spaniel corgi American pit bull terrier standard schnauzer Australian cattle dog Welsh corgi German pinscher Portuguese water dog
boxer bulldog collie German shepherd German wirehaired pointer giant schnauzer golden retriever Irish setter Labrador retriever standard poodle
rottweiler Irish wolfhound Bernese mountain dog Saint Bernard Great Pyrenees Great Dane bullmastiff bloodhound Newfoundland greater Swiss mountain dog
To complete the table showing the dog year equivalent for each breed from 2-5 human years, you would need to use the chart provided and determine the age increase for each size category.
Here is an example of how you could complete the table using the given information:
| Dog Breed | Size | 2 Human Years | 3 Human Years | 4 Human Years | 5 Human Years |
|--------------|--------|---------------|---------------|---------------|---------------|
| Border Terrier | Small | 23 dog years | 27 dog years | 31 dog years | 35 dog years |
| Cocker Spaniel | Medium | 24 dog years | 29 dog years | 34 dog years | 39 dog years |
| Boxer | Large | 22 dog years | 28 dog years | 34 dog years | 40 dog years |
| Great Dane | Giant | 20 dog years | 27 dog years | 34 dog years | 41 dog years |
To write an expression to model each breed's age in dog years, you can use the formula:
Age in dog years = (x - 2) * Age increase each year after 2
Here is an example for the Border Terrier:
Age in dog years = (x - 2) * 4
To choose a realistic old age for people (step 4), you can research the average lifespan for each breed and select an age based on that information.
For each expression you write, plug in the chosen old age for humans (step 4) and set the expression equal to A. Then, solve the equation to find dog years equivalent to the old age.
For example, if the chosen old age for humans is 80, the equation for the Border Terrier would be:
(80 - 2) * 4 = A
You would solve this equation to find the dog years equivalent for an 80-year-old Border Terrier.
By completing the table, solving the equations, and researching average dog lifespans, you can develop a convincing argument for why the method described in the chart is better than the traditional method of multiplying by 7. This can be done by comparing the results and showing how they align more closely with the average lifespans of each breed.
To complete the table showing the dog year equivalent for each breed from 2-5 human years, you will need to apply the given conversion method for each size category.
1. Choose a dog breed in each size category. For example, you could choose:
- Size Small: Chihuahua
- Size Medium: Cocker Spaniel
- Size Large: Boxer
- Size Giant: Saint Bernard
2. Complete the table as follows:
| Breed | 2 Human Years | 3 Human Years | 4 Human Years | 5 Human Years |
|-------------------|---------------|---------------|---------------|---------------|
| Chihuahua | 23 dog years | 27 dog years | 31 dog years | 35 dog years |
| Cocker Spaniel | 24 dog years | 29 dog years | 34 dog years | 39 dog years |
| Boxer | 22 dog years | 28 dog years | 34 dog years | 40 dog years |
| Saint Bernard | 20 dog years | 27 dog years | 34 dog years | 41 dog years |
3. To write an expression to model each breed's age in dog years, we can use the formula:
(x - 2) * age increase + age at 2 in dog years
- For the Chihuahua: (x - 2) * 4 + 23
- For the Cocker Spaniel: (x - 2) * 5 + 24
- For the Boxer: (x - 2) * 6 + 22
- For the Saint Bernard: (x - 2) * 7 + 20
4. Choose a really old age for people, for example, 90 years old.
5. Plug in the chosen value into each expression and set it equal to A, the dog's age:
- For the Chihuahua: (90 - 2) * 4 + 23 = A
- For the Cocker Spaniel: (90 - 2) * 5 + 24 = A
- For the Boxer: (90 - 2) * 6 + 22 = A
- For the Saint Bernard: (90 - 2) * 7 + 20 = A
6. Solve each equation to find the dog's age:
- For the Chihuahua: (88) * 4 + 23 = 355, A = 355 dog years
- For the Cocker Spaniel: (88) * 5 + 24 = 464, A = 464 dog years
- For the Boxer: (88) * 6 + 22 = 536, A = 536 dog years
- For the Saint Bernard: (88) * 7 + 20 = 636, A = 636 dog years
These solutions represent the dog's age in dog years when they reached the chosen age of 90 in human years. Add these values to the table under the "5 Human Years" column.
7. Use the solutions to develop a convincing argument for why the method described in the chart is better than the traditional method by comparing the dog year equivalents for different breeds at the same human age. Consider the average lifespan for each dog breed as a supporting factor in your argument.
8. Use the table, equations, solutions, and arguments to create your debate presentation or other form of submission.