Name:________________                Date:_______________

With a partner use your pre-programmed microbit to simulate the capture-recapture method.  The capture-recapture method is a strategy used by biologist to estimate the total size of an animal population.  Biologist capture and tag a certain number of animals.  They release the animals and capture another group of animals.  The new group of captured animals may include some of the original tagged animals.  The captured animals are released and the and process repeats.

1. To run the simulation, plug in the micro:bit and record the displayed number representing the number of tagged animals in the space below.

Tagged animals: _____________

1. Run several recapture trials and record your results below:

To run a trial:

1. First press the “A” button on the micro:bit. The number displayed represents the total number of animals recaptured
2. Then press the “B” button on the micro:bit. The number displayed represents the number of tagged animals in the recapture sample
3. Record the ratio of tagged animals in the sample to the sample size
4. Press “A+B” to see the trial number.
5. Repeat steps 1-3 to do another trial.

Trial #	Recapture Sample Size	# of Tagged Animals in Sample	Ratio of tagged animals in the sample to the total sample size
Ex.	20	12

1. To estimate the total population solve the proportion below for each trial and record in the table below

1. Find the average of the estimated total populations from your trials

Average:________________________