# Mathematics - Class 4 / Grade 4

- Highest Common Factor
### Highest Common Factor

Math - Class 4 – Highest Common Factor- Key Points/Notes/Worksheets/Explanation/Lesson/Practice Questions Tags - Greatest Common Divisor (GCD), Highest Common Factor (HCF), Greatest Common Factor (GCF), Highest Common Divisor (HCD),Examples on highest common factor, How to calculate HCF by division method, HCF definition, HCF by prime factorization, HCF by long division method, HCF worksheet PDF, Quiz on HCF, HCF practice page. Determine the HCF of the pairs by finding factors. Find the HCF by prime factorization method. Find HCF by division methodHighest Common Factor

The Greatest Common Divisor (GCD) is also known as the Greatest Common Factor (GCF), Highest Common Factor (HCF), Greatest Common Measure (GCM), or Highest Common Divisor.

HCF with Prime Factorization Method

Example: Find the HCF of 15 and 35.

Prime factors of 15 = 3, 5

Prime factors of 35 = 5, 7

Common factor of 15 and 35 = 5

Therefore, Highest common factor (H.C.F) of 15 and 35 = 5

HCF by Division Method

__Step1:__Divide the two given numbers together by their common prime factors.__Step2:__Stop dividing when there is no common prime factor left.__Step3:__Multiply the common prime factors to find the HCF.Example 1: Find the HCF of 12 and 18.

Now we cannot divide further with common factor.

Multiply common factor to get HCF = 2 x 3 = 6

So, HCF of 12 and 18 = 6

Example 2: Find the HCF of 12, 36 and 48.

Now we cannot divide further with common factor.

Multiply common factor to get HCF = 2 x 2 x 3 = 12

So, HCF of 12, 36 and 48 = 12

HCF by Long Division Method

The method of long division is more useful for large numbers.

__Step1:__Identify the larger number from the given two numbers and divide the larger number by the smaller number.__Step2:__Now remainder become divisor and the previous divisor become the dividend. Divide the new dividend with new divisor.__Step3:__Continue this process till we get remainder as 0.__Step4:__The last divisor in this process is the H.C.F of the two numbers

Example: Find HCF of 18 and 30

__Step1:__Start dividing 30 by 18__Step2:__Now, remainder 12 becomes the divisor and previous divisor 18 has become the dividend. Divide 18 by 12.__Step3:__Now the new remainder 6 becomes the divisor and previous divisor 12 has become the dividend. Divide 12 by 6.__Step4:__Now remainder is 0. So, further division is not possible and the last divisor 6 becomes the HCF of 18 and 30.**Download to practice offline.**