Pi is 3-The Daily Ledger

Pi is 3 is a misunderstanding that the Japanese public believed that, due to the revision of the Japanese Curriculum guideline in 2002, the approximate value of pi (π), which had previously been taught as 3.14, is now taught as 3 in arithmetic education. In fact, this is not true, and even after the revision, the approximate value of pi is still taught as 3.14.

In the Japanese Curriculum guideline published in December 1998 and implemented in 2002, regulations such as the limitation on the number of digits for decimal multiplication were changed. Although the new regulations did not change the fact that pi was to be calculated using "3.14," they added the statement that "3 is used for the purpose."

Pi is 3

At that time, many people believed elementary school students were forced to hand calculate pi as "3", and believed that is a typical example of the negative effects of a relaxed education. This misunderstanding was not easily resolved.

Pi is 3

Overview

In the fall of 1999, a major cram school company launched a major campaign with advertisements that read "The formula for finding the area of a circle: radius x radius x 3!", "Calculate the quadrature of a circle with pi as approximately 3 instead of 3.14."

Pi is 3

The mass media also picked up on this issue, and it became widely wrong recognized in society that "as a result of the relaxed education system, pi is now taught as 3.

As a criticism of the decline in scholastic achievement and the relaxed education system, "Pi is 3" was widely covered in weekly and monthly magazines and other mathematics-related journals.

Details

"Use 3 if fits your purpose" guideline

The Japanese Curriculum guideline was started as a guide only, but at some point, they came to be considered legally binding. In addition to this, there was also a so-called "restrictive provision" that "has to teach without excesses or deficiencies of what the guidelines say." This statement was carried over to the 1998 revision (implemented in 2002 for elementary schools.)

"To process using 3 for the purpose" assumed for, If you want to make an estimate, calculate quickly by 3. The decimal point is not calculated from the beginning, and a rough guess is made with 3 to reduce the possibility of calculation errors. When want to approximate the perimeter or area of an object that is similar to a circle, calculate the circumference and area of the circle using pi as 3. One interpretation is that they expect to develop the ability to make appropriate judgments and process the information according to the situation and application.

Issues with the 1998 Revised Guidelines

As part of the so-called "relaxed education," the content of arithmetic learning in multiplication, division, and decimals was reduced, while calculators were allowed to be used from the arithmetic learning stage.

On the other hand, because relaxed education reduced the time for learning but not the areas of learning, many people believed that, students were forced by guideline to use 3 instead of 3.14 as the approximate number of Pi for calculating. However, it was a misunderstanding.

In addition, the use of calculators, which was allowed from the 5th grade under the previous teaching guidelines, was allowed from the 4th grade and calculations using 3.14 were possible even with a calculator.

Limit the number of decimal digits

In the 1998 Revised Curriculum guideline in Japan, the calculation of decimals in the fifth grade of elementary school is,

Because of the above limitation, this led to the misunderstanding that 3 must be used as pi. But even if decimals were limited to 1/10th of a place, the pi used would still be 3.1, which does not define pi as 3.

The misunderstanding that "pi is approximately 3"

At that time, in the fall of 1999, a major cram school company released the following advertisement.

They conducted a major campaign in the Tokyo metropolitan area, and the media covered it extensively.

This led to widespread public awareness of the misunderstanding that pi is now taught as 3 because of the relaxed education system.

Akito Arima, who promoted "relaxed education" as the Minister of Education at the time, repeatedly said, "I was stunned by that," and regretted "my failure to go around the country and explain it in detail."