Divisors of 21

When we talk about the divisors of a number, we are referring to the numbers that can divide the original number evenly, without leaving a remainder. In this article, we will explore what divisors are, how to find them, and present a list of the divisors for the number 21. The goal is to make this topic easy to understand for everyone.

To understand divisors, we first need to look at the concept of division. When we divide one number by another, we have three important terms:

1. Dividend: This is the number we want to divide.
2. Divisor: This is the number we are dividing by.
3. Quotient: This is the result of the division.

For example, consider the number 21:

• If we divide 21 by 3, we are saying:

  21 (dividend) / 3 (divisor) = 7 (quotient)

In this case, 21 is divided by 3, and we get a whole number, which means 3 is a divisor of 21 because it divides 21 evenly.

Now, let’s dive into how to calculate the divisors of 21. We will take the number 21 and divide it by every integer starting from 1 all the way up to 21 itself. This means we are checking each number to see if it can divide 21 without leaving a remainder.

Step-by-Step Guide to Finding the Divisors of 21:

1. Start with 1 and go up to 21.
2. For each number, we’ll divide 21 by that number.
3. If the result (the quotient) is a whole number, then that number is a divisor of 21.

Division Calculations for 21:

• 21 / 1 = 21 (whole number: yes, 1 is a divisor)
• 21 / 2 = 10.5 (whole number: no)
• 21 / 3 = 7 (whole number: yes, 3 is a divisor)
• 21 / 4 = 5.25 (whole number: no)
• 21 / 5 = 4.2 (whole number: no)
• 21 / 6 = 3.5 (whole number: no)
• 21 / 7 = 3 (whole number: yes, 7 is a divisor)
• 21 / 8 = 2.625 (whole number: no)
• 21 / 9 = 2.333 (whole number: no)
• 21 / 10 = 2.1 (whole number: no)
• 21 / 11 = 1.909 (whole number: no)
• 21 / 12 = 1.75 (whole number: no)
• 21 / 13 = 1.615 (whole number: no)
• 21 / 14 = 1.5 (whole number: no)
• 21 / 15 = 1.4 (whole number: no)
• 21 / 16 = 1.3125 (whole number: no)
• 21 / 17 = 1.235 (whole number: no)
• 21 / 18 = 1.1667 (whole number: no)
• 21 / 19 = 1.105 (whole number: no)
• 21 / 20 = 1.05 (whole number: no)
• 21 / 21 = 1 (whole number: yes, 21 is a divisor)

From our calculations, we can summarize which numbers fit as divisors of 21.

List of Divisors of 21:

• 1
• 3
• 7
• 21

In conclusion, the divisors of the number 21 are 1, 3, 7, and 21. These are the numbers that can divide 21 without leaving any remainder. Understanding divisors is useful in many areas of math, such as fractions and factors, and helps to build a solid foundation in number theory.