Try three great activities for Pi Day. You’ll enjoy teaching this elusive number (3.14…) on March 14 (3/14) in your upper elementary classroom.

## Activities for Pi Day in Ms. Sneed’s Classroom

Our favorite fourth grade teacher sat at the side table with her teaching partner. “Let’s get started on our March plans,” she said.

Mr. Frank motioned to the materials covering the table. “Looks like we’ll be working on measurement – specifically, activities for Pi Day,” he chuckled.

“Of course!” Ms. Sneed responded. “March 14th, or 3/14, is one of my favorite days of the year. After all, I enjoy every opportunity to channel my inner math geek.”

### Discovering 3.14

She pointed to a variety of round objects stacked on the table. “First, our kids will find 3.14 on their own.”

Mr. Frank sifted through a file and pulled out the corresponding worksheets. “These first few pages will help us prepare our students for the activity for Pi Day. First, we’ll introduce parts of a circle: center, radius, diameter, and circumference. Second, we’ll review how to find the mean, or average.”

“Then,” Ms. Sneed said, her eyes sparkling, “we’ll set them loose! In pairs, they’ll use tape measures to find the circumference and diameter of ten circular items. Of course, we’ll let them pick items from the table – like these paper plates – but they might also measure the round base of the globe, or the base of the trash can.”

Her teaching partner pulled out another page. “Right, and they’ll record their data on this page. Then they’ll find the mean of each column. Finally, they’ll use a calculator to divide the average circumference by the average diameter. With any luck – and good measuring – they should come up with something close to 3.14.”

“As a grand finale,” said Ms. Sneed, “we’ll also list the findings of all groups on the board. Then we can find the average of those. That should get us even closer to it.”

“Last year,” Mr. Frank added, “some of my kids’ data was out of whack. Therefore, I taught them to throw out outliers. And that helped us get even closer.”

He sat back with a satisfied look on his face. “In my humble opinion, this is one of the best activities for Pi Day.”

“True, but there’s more,” his teaching partner replied.

### Historical Timeline

“After they struggle to find pi, they’ll understand how mathematicians throughout history have worked on it,” she said.

Ms. Sneed pulled out another file. “What a perfect time to build a timeline. Each child will receive a different page featuring one historical breakthrough. They’ll mark the world map with the location of the discovery. Then they’ll add it to our timeline. This activity for Pi Day focuses on something we rarely teach: the history of math.”

### Statistical Analysis – Tally Tables, Frequency Tables, and Line Plots

Mr. Frank reached into his backpack. “As you know, we’ve been looking for a few statistics activities for Pi Day. And – ta-da! – I found one. For this frequency project, students list the first hundred digits of pi in a tally table, transfer them to a frequency table, and then create a line plot.”

As he laid the pages out in front of his colleague, she beamed. “I love this! Kids tally the digits in groups of five. Then they check them off. That way, they won’t lose track.”

“Then,” Mr. Frank added, “they move the data to a frequency table and plot the data on a line plot. Like I said – an authentic statistics project!”

### Culminating the Activities for Pi Day

Now Ms. Sneed pulled out one more sheet of paper. “To wrap our activities for Pi Day, we’ll go over this background information. It reviews key concepts.”

She read the information outloud:

“Pi can also be written using ∏, a letter in the Greek alphabet. It represents a quantity that can be used to figure the circumference (2∏r, or two times pi times the radius) and the area (∏r^{2}, or pi times the radius of a circle squared).

“For everyday purposes, people often say that pi equals 3.14. That, however, is only an estimate. Pi is an irrational number. It cannot be written as a whole number or fraction. As a matter of fact, pi’s exact value has puzzled mathematicians for thousands of years.

“The earliest record of pi comes from text on the *Rhind Papyrus*, which was written in Egypt around 1650 BC. At that time, its value was estimated to be 3.1605. A clay tablet from Iraq in 1600 BC estimated 3.125.

“Mathematicians in ancient Babylon claimed that pi’s value was 25/8, or 3.125. The Egyptians though it might be 16/9, or 3.16. Around 250 BC, a famous Greek mathematician named Archimedes proved that pi is greater than 223/71 but less than 22/7.

“Since then, people from around the world have worked to find the exact value of this elusive number. Around 1200, Fibonacci (Italy) said that pi equaled 3.1418. In 1596, Ludolph van Ceulen calculated it to 20 digits, and in 1706, John Machin (Great Britain) found 100 digits. Later, in 1873, William Shanks calculated 707 digits.

“Finally, people started using technology to help them calculate pi. In 1949, John Wrench and Levi Smith (USA) found 1120 digits with a calculator. After that, mathematicians used computers to try to figure out pi. However, no specific number has been found. The latest confirmed estimate (2021) contains nearly 63 trillion decimal places.

“And so, the quest to understand pi continues. Today, we celebrate Pi Day on March 14 (3/14) to honor this powerful and mysterious number.”

### The Icing on the Cake – I Mean, Pi

Pi Day (3/14) is approaching. Catch the spirit! You can see one million digits of pi, buy a t-shirt, or learn more at the official Pi Day site.

If you, like Ms. Sneed, love teaching fourth grade math, grab a few activities for Pi Day and get started!