Migration Rate Math
| Practice
How Many Can You Count in a Minute? |
Example with Answers |
Record
Flight Who Will See the Record Flight This Fall? |
My
Records |
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This
Fall's Records: |
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Background
Lesson
This lesson helps students make monarch migration observations that are
valuable and useful. When students count the number of monarchs they observe
—and they also record the length of time they were observing
— their migration observations are far more valuable. This way,
observations can be compared meaningfully with a person's own day-to-day
records and to records from other locations. Observations have little
comparative value if they are not made in a standardized way.
Laying
the Groundwork
Scientists rely on carefully gathered data to help answer their questions,
test their hypotheses, and develop and justify explanations. When data
collection is done in a uniform way, scientists can recognize patterns,
make accurate comparisons or generalizations, and/or have confidence in
results. Because Journey North is a data-driven project, students need
practice gathering accurate and useful information.
Exploration
1. Consider the number of monarchs observed.
First, have students consider the information that is most commonly provided,
the number of monarchs a person sees. Write the following on the blackboard:
Observer A: I saw 80 monarch butterflies.
Observer B: I saw 79 monarch butterflies.
Ask students, Which observer saw more monarch butterflies? (Observer A.)
2.
Consider the length of the observation period.
Now add the following information about each observation:
Observer A: I was watching from 8 am to 4 pm.
Observer B: I was watching from 8 am to 9 am.
Ask students, Describe the new information that was added. Ask, What do we know that we did not know before? (We know how long each observer was watching.)
Why is this new information important? What does it tell you about the migration in each place? (This is important because only if we know how much time a person was watching we can compare migration sightings from one time to the next and from one place to the next.)
3.
Calculate the length of each observation.
Now ask students, Exactly how long was each observer watching? Give
your answer in hours.
Observer A: 8 am to 4 pm = 8 hours
Observer B: 8 am to 9 am = 1 hour
4.
Introduce the concept of the migration rate.
Intuitively, students will conclude that the migration was probably much
stronger where Observer B was watching. Help them find language to explain
this. Ask, Where would you rather have been watching monarch migration
with Observer A or Observer B? Explain why.
What words could we use to make the two observations easier to compare? Give students time to develop the concept of “monarchs per hour.” If they need help, give them a sentence starter such as: Observer A saw ___ in ___ but Observer B saw ___ in ___.
5.
Calculate the migration rate (in monarchs per hour).
Have students complete the calculations and write a sentence
so the observations can be compared easily.
- Observer A saw 1 monarch per hour.
- Observer B saw 79 monarchs per hour.
| Migration Rate |
| 1) Number of monarchs and 2) length of time observing. |
6.
Find the migration rate for actual observations!
Collect
this
fall's most impressive observations
from the migration maps and weekly
updates. Record
them on this data sheet. See:
7. Challenge
students to look at data carefully.
While reviewing observations reported on the migration
maps ask students:
- Which observations are the most valuable?
- Which observations leave you with questions?
- Can you find observations that are missing information you need in order to calculate the migration rate? If so, what information is missing?
