1π=3. 14、2π=6.28、3π=9.42、4π= 12.56、5π= 15.7、6π= 18.84、7π=2 1.98、8π=25. 12、9π=28.26、 10π=3 / kloc-0/.4、 1 1π=34.54、 12π=37.68、 13π=40.82、 14π=43.96。

1. The definition and significance of pi;

Pi is a mathematical constant, expressed by the letter π, which represents the ratio of the circumference to the diameter of a circle. It is an irrational number, that is, infinite acyclic decimal, and its value is about 3. 14 15926 ... Pi is widely used in geometry, physics, engineering and other fields, and is the basis of many mathematical and scientific problems.

2. The memory method of pi:

Music memory method: convert the value of pi into a specific melody, sing it with syllables in your mind, and remember the numerical order by using the rhythm of music. Memory method of formula table: write simple and easy-to-remember poems or songs according to the law, and connect the number sequence of pi with words.

3. Classification and examples of formula tables:

Rhyme formula table: remember by rhyme, such as "3. 14 15, 926535, 897932, 384626". Alphabet formula table: remember each numerical value with the first letter of pinyin, such as "31415,926535,897932,384626".

Sentence formula table: relying on specific sentences and poems, remember the digits of pi through the association of words, such as "in the ancient world, pi has been calculated." This small circle, 3. 14 is a soft number. 159265, you frown. As soon as I passed 979, I found 32. 384626, Yuanyuan is not a classmate. "

4. Use the formula table to remember the advantages and disadvantages of pi:

Advantages: Formula table can turn boring series into interesting poems or songs, and provide a simple and easy memory method to help people remember pi more easily. Disadvantages: although the formula table memory method is convenient, it is not accurate, and it can only approximate the value of pi, not accurate to every decimal place. At the same time, the memory method of formula table is not suitable for occasions that need high precision calculation.