5 Questions
What is 20 in terms of its factors?
A primal number
What is special about the sum of the proper divisors of 20?
It is greater than 20
What is the atomic number of calcium?
20
What is the typical number of years in a generation?
20
How many face cards are in a standard deck of playing cards?
20
Study Notes
Properties of the Number 20
- 20 is an abundant number, a number for which the sum of its proper divisors (excluding the number itself) is greater than the number itself.
- 20 is a primal number, a number that is not a power of a prime number.
- 20 is a tetrahedral number, the sum of the internal diagonals of a tetrahedron.
In Science
- 20 is the atomic number of calcium.
In Everyday Life
- 20 is the typical number of years in a generation.
- In many countries, 20 is the age of majority, the age at which a person is considered an adult.
- A standard deck of playing cards has 20 face cards (4 suits x 5 face cards per suit).
In History
- The twentieth century began on January 1, 1901, and ended on December 31, 2000.
Properties of the Number 20
- An abundant number because the sum of its proper divisors is greater than the number itself.
- A primal number, meaning it's not a power of a prime number.
- A tetrahedral number, which is the sum of the internal diagonals of a tetrahedron.
In Science
- The atomic number of calcium is 20.
In Everyday Life
- A typical generation lasts for 20 years.
- In many countries, 20 is the age of majority, marking the transition to adulthood.
- A standard deck of playing cards contains 20 face cards (4 suits × 5 face cards per suit).
In History
- The 20th century began on January 1, 1901, and ended on December 31, 2000.
Explore the unique properties of the number 20, including its abundance, primality, and tetrahedral characteristics. Learn about its significance in science and everyday life.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
