The HCF of 1 and 2 is 1. Listing common factors, prime factorisation, and long division are the three most frequent methods used for calculating the HCF of 1 and 2. The highest number that divides 1 and 2 perfectly and without leaving a remainder is called the HCF of 1 and 2. The factor of 1 is 1 itself and factors of 2 are 1 and 2.
Also read: Highest common factor
What is the HCF of 1 and 2?
The answer to this question is 1. This article shows how to find the HCF of 1 and 2 using various methods for your reference. The greatest of all their common factors is the Highest Common Factor (HCF) of two or more numbers.
How to Find HCF of 1 and 2?
There are three methods to find the HCF of 1 and 2:
- Prime Factorisation
- Long Division method
- Listing common factors
HCF of 1 and 2 by Prime Factorisation Method
The prime factorisation of 1 and 2 is given by:
Prime factorisation of 1 = 1
Prime factorisation of 2 = 2
Hence, the HCF of 1 and 2 is 1.
HCF (1, 2) = 1
HCF of 1 and 2 by Long Division Method
The divisor that we get when the remainder is 0 after doing long division repeatedly is the HCF of 1 and 2.
No further division can be done.
Hence, HCF (1, 2) = 1
HCF of 1 and 2 by Listing Common Factors
To calculate the HCF of 1 and 2 by listing common factors, list the factors as shown below:
Factor of 1: 1
Factors of 2: 1, 2
Since 1 is the only common factor between 1 and 2, the Highest Common Factor of 1 and 2 is 1.
Related Articles
Video Lesson on Properties of HCF and LCM
HCF of 1 and 2 Solved Example
Question: Find the highest number that divides 1 and 2 exactly.
Solution:
The highest number that divides 1 and 2 exactly is their Highest Common Factor .i.e HCF of 1 and 2.
Factors of 1 and 2:
Factors of 1 = 1
Factors of 2 = 1, 2
Therefore, the HCF of 1 and 2 is 1.
Frequently Asked Questions on HCF of 1 and 2
Q1
What is the HCF of 1 and 2?
The HCF of 1 and 2 is 1. To calculate the Highest Common Factor (HCF) of 1 and 2, we need to factor each number (factor of 1 = 1; factors of 2 = 1, 2) and choose the highest factor that exactly divides both 1 and 2 .i.e 1.
Q2
How to find the HCF of 1 and 2 by long division method?
To find the HCF of 1 and 2 using the long division method, 2 is divided by 1. The corresponding divisor (1) when remainder equals 0 is the HCF.
Q3
If the HCF of 2 and 1 is 1, find its LCM.
HCF(2, 1) × LCM(2, 1) = 2 × 1
The HCF of 2 and 1 = 1
⇒ 1 × LCM(2, 1) = 2
Therefore, LCM = 2
Q4
What is the relation between LCM and HCF of 1 and 2?
The following equation can be used to express the relation between LCM (Least Common Multiple) and HCF (Highest Common Factor) of 1 and 2 .i.e HCF × LCM = 1 × 2.
Q5
What are the methods to find the HCF of 1 and 2?
There are three commonly used methods to find the HCF of 1 and 2. They are:
Long Division
Listing Common Factors
Prime Factorisation
