STANDARDS

CCSS: 3.OA.A.1, 3.OA.A.3; MP4, MP7

TEKS: 3.4D

MULTIPLICATION MODELS

Nuts for Organization

Squirrels sort and track their stashes of nuts

November 2018

By Alexa Kurzius

Courtesy of Ryan Hoang/UC Berkeley

Mikel Delgado

Fox squirrels roam the campus of the University of California, Berkeley. They climb trees, hop across the grass, and bury nuts to eat later. Scientist Mikel Delgado knows this because she has kept track of where the animals went!

Delgado studies how animals behave and process information. When she was a graduate student at the university, she wanted to know whether squirrels bury their nuts with any intention or pattern.

To find out, Delgado conducted an experiment along with other students. The team labeled almonds, hazelnuts, pecans, and walnuts. Then they gave each type of nut to 45 squirrels. They tracked each squirrel using GPS tags. When a squirrel buried the nuts for a future snack, the scientists noted the location. Last, they mapped the results.

The group found that squirrels bury nuts in different places depending on their type and size. Delgado thinks this might help the squirrels remember where the nuts are so they can find their snacks later.

“Like us, animals have to solve problems,” she says. And “those problems are really dependent on the environment that animal lives in.”

Squirrels must bury thousands of nuts each year to survive. Then they need to recover their food and keep other animals from stealing their nuts. “It’s an interesting problem,” she says.

Delgado grew to love squirrels through her research. “Squirrels are really cool, plus they’re everywhere,” she says. Her favorite was a mother squirrel that the researchers nicknamed Flame. Her bold personality made her a great subject for their experiment, Delgado says.

urban wildlife is a fascinating window into the natural world, and Delgado encourages everyone to take notice. “These animals have learned to survive around humans,” she says.

Multiplication Diagrams

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MATH TALK:

In what situations might you use multiplication when studying wild animals?

Multiplication Models

Now You Try It

Use arrays and equations to solve the following problems on a separate sheet of paper.

1A.

Scientists gave nuts to 8 male squirrels one day and 8 female squirrels another day. Draw an array to show the total number of squirrels.

1B.

Use your array to write an equation.

2A.

All squirrels received 4 nuts of each type. One squirrel buried only the almonds, hazelnuts, and pecans. Draw an array to show the total number of nuts it buried.

2B.

Use your array to write an equation.

3A.

In total, the scientists worked with 24 female squirrels. Draw 3 different arrays to represent a product of 24.

3B.

Write an equation for each of your arrays.

One squirrel took part in the experiment twice. Each time, the animal received 16 nuts. How many total nuts did the animal get over the course of both experiments?

Ten female squirrels and 18 male squirrels stashed nuts in multiple locations. A student says you can make 2 different arrays to show this total number of female and male squirrels. Correct the mistake and explain why the student is incorrect.