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Last updated on September 9, 2025
The natural numbers greater than 1 are called prime numbers. Prime numbers have only two factors, 1 and the number itself. Besides math, we use prime numbers in many fields, such as securing digital data, radio frequency identification, etc. In this topic, we will learn about the prime numbers 10 to 20.
A prime number is a natural number with no positive factors other than 1 and the number itself. A prime number can only be evenly divisible by 1 and the number itself. Here are some basic properties of prime numbers:
A prime number chart is a table showing the prime numbers in increasing order. The chart simply includes all the prime numbers up to a certain limit for identifying the prime numbers within a range.
For kids, it will be less difficult to understand the prime numbers through the chart. The significance of this prime number chart is used in different fields like the foundation of mathematics and the fundamental theorem of arithmetic.
The list of all prime numbers from 10 to 20 provides a comprehensive view of numbers in this range that can only be divided by 1 and the number itself.
The prime numbers in the range of 10 to 20 include 11, 13, 17, and 19.
Prime numbers and odd numbers are the numbers that are only divisible by 1 and the number itself. They cannot be evenly divisible by 2 or other numbers.
2 is the only even prime number, which divides all the non-prime numbers. Therefore, except 2, all prime numbers are considered as the set of odd numbers.
Prime numbers are a set of natural numbers that can only be divided by 1 and the number itself. Here are the two important ways to find whether a number is prime or not.
To find whether a number is prime or not, we use the divisibility method to check. If a number is divisible by 2, 3, or 5, then it will result in a non-prime number. Prime numbers are only divisible by 1 and themselves, so if a number is divisible by the number itself and 1, it is meant to be a prime number. For example: To check whether 17 is a prime number,
Step 1: 17 ÷ 2 = 8.5 (remainder ≠ 0)
Step 2: 17 ÷ 3 = 5.66 (remainder ≠ 0)
Step 3: 17 ÷ 5 = 3.4 (remainder ≠ 0) Since no divisors are found, 17 is a prime number.
The prime factorization method is the process of breaking down the composite number into the product of its prime factors. The method of prime factorization helps to identify the prime numbers up to 20 by building the smallest blocks of any given number. For example: To verify 20 is not a prime: Let's break it down into the smallest prime numbers until it can’t divide anymore.
Step 1: 20 ÷ 2 = 10
Step 2: Now, we divide 10, 10 ÷ 2 = 5
Step 3: At last, take 5. 5 ÷ 5 = 1 (since 5 is a prime number, and dividing by 5 gives 1)
Therefore, the prime factorization of 20 is: 20 = 2^2 × 5.
Rule 1: Divisibility Check:
Prime numbers are natural numbers that are greater than 1 and have no divisors other than 1 and the number itself. In the divisibility check rule, we check whether the number is divisible by 2, 3, 5, and 7. If it's divisible by these numbers, then it's not a prime number.
Rule 2: Prime Factorization:
In this prime factorization method, we break down all the numbers into their prime factors, showing them as the product of prime numbers.
Rule 3: Sieve of Eratosthenes Method:
The method, sieve of Eratosthenes, is an ancient algorithm used to find all prime numbers up to a given limit. First, we list all the numbers from 10 to 20. Then start with the first prime number, 2. Mark all the multiples of 2 as non-prime. Repeat the process for the next unmarked prime number and continue until you reach the square root of 20, approximately 4.47. The remaining unmarked numbers are the prime numbers. plain_heading7
While working with the prime numbers 10 to 20, children might encounter some errors or difficulties. We have many solutions to resolve those problems. Here are some given below:
Is 13 a prime number?
Yes, 13 is a prime number.
The square root of 13 is √13 = 3.6, we check divisibility by primes less than 3.6 (2, 3).
13 ÷ 2 = 6.5
13 ÷ 3 = 4.33
Since 13 is not divisible by any of these numbers, 13 is a prime number.
Emma is trying to pick a number for her art project that is a prime number between 10 and 20. Which prime number should she pick?
Emma can pick 11, 13, 17, or 19 for her art project.
Prime numbers are natural numbers that are greater than 1 and have no divisors other than 1 and the number itself.
The prime numbers between 10 and 20 are 11, 13, 17, and 19.
A teacher challenges her students: Find the prime number that is closest to 18.
19 is the prime number which is closest to 18.
19 is a prime number because it is only divisible by 1 and the number itself.
The next prime number before 19 is 17, which is also close to 18, but 19 is the closest prime number to 18.
Hiralee Lalitkumar Makwana has almost two years of teaching experience. She is a number ninja as she loves numbers. Her interest in numbers can be seen in the way she cracks math puzzles and hidden patterns.
: She loves to read number jokes and games.