Last updated on July 28th, 2025
The GCF is the largest number that can divide two or more numbers without leaving any remainder. GCF is used to share items equally, group or arrange items, and schedule events. In this topic, we will learn about the GCF of 36 and 81.
The greatest common factor of 36 and 81 is 9. The largest divisor of two or more numbers is called the GCF of the numbers. If two numbers are co-prime, they have no common factors other than 1, so their GCF is 1. The GCF of two numbers cannot be negative because divisors are always positive.
To find the GCF of 36 and 81, a few methods are described below:
Steps to find the GCF of 36 and 81 using the listing of factors:
Step 1: Firstly, list the factors of each number
Factors of 36 = 1, 2, 3, 4, 6, 9, 12, 18, 36.
Factors of 81 = 1, 3, 9, 27, 81.
Step 2: Now, identify the common factors of them Common factors of 36 and 81: 1, 3, 9.
Step 3: Choose the largest factor.
The largest factor that both numbers have is 9.
The GCF of 36 and 81 is 9.
To find the GCF of 36 and 81 using Prime Factorization Method, follow these steps:
Step 1: Find the prime factors of each number:
Prime Factors of 36: 36 = 2×2×3×3 = 2²×3²
Prime Factors of 81: 81 = 3×3×3×3 = 3⁴
Step 2: Now, identify the common prime factors.
The common prime factors are: 3×3 = 3²
Step 3: Multiply the common prime factors 3² = 9.
The Greatest Common Factor of 36 and 81 is 9.
Find the GCF of 36 and 81 using the division method or Euclidean Algorithm Method. Follow these steps:
Step 1: First, divide the larger number by the smaller number.
Here, divide 81 by 36 81 ÷ 36 = 2 (quotient),
The remainder is calculated as 81 − (36×2) = 9
The remainder is 9, not zero, so continue the process
Step 2: Now divide the previous divisor (36) by the previous remainder (9)
Divide 36 by 9 36 ÷ 9 = 4 (quotient), remainder = 36 − (9×4) = 0
The remainder is zero, the divisor will become the GCF.
The GCF of 36 and 81 is 9.
Finding GCF of 36 and 81 looks simple, but students often make mistakes while calculating the GCF. Here are some common mistakes to be avoided by the students.
A gardener has 36 roses and 81 lilies. She wants to plant them in rows with an equal number of flowers. What is the largest number of flowers she can have in each row?
We should find the GCF of 36 and 81 GCF of 36 and 81
3² = 9.
She can plant 9 flowers in each row.
36 ÷ 9 = 4
81 ÷ 9 = 9
There will be 9 flowers in each row, with 4 rows of roses and 9 rows of lilies.
As the GCF of 36 and 81 is 9, the gardener can have 9 flowers in each row.
Now divide 36 and 81 by 9.
There will be 4 rows of roses and 9 rows of lilies, each with 9 flowers.
A baker has 36 chocolate muffins and 81 vanilla muffins. He wants to package them into boxes with the same number of muffins. What is the largest number of muffins that can be in each box?
GCF of 36 and 81 3² = 9. So each box will have 9 muffins.
There are 36 chocolate and 81 vanilla muffins.
To find the total number of muffins in each box, we should find the GCF of 36 and 81.
There will be 9 muffins in each box.
A tailor has 36 meters of fabric for dresses and 81 meters for shirts. She wants to cut both fabrics into pieces of equal length, using the longest possible length. What should be the length of each piece?
For calculating the longest equal length, we have to calculate the GCF of 36 and 81
The GCF of 36 and 81
3² = 9.
The fabric is 9 meters long.
For calculating the longest length of the fabric first we need to calculate the GCF of 36 and 81 which is 9.
The length of each piece of fabric will be 9 meters.
A carpenter has two wooden planks, one 36 cm long and the other 81 cm long. He wants to cut them into the longest possible equal pieces, without any wood left over. What should be the length of each piece?
The carpenter needs the longest piece of wood GCF of 36 and 81
3² = 9.
The longest length of each piece is 9 cm.
To find the longest length of each piece of the two wooden planks, 36 cm and 81 cm, respectively.
We have to find the GCF of 36 and 81, which is 9 cm.
The longest length of each piece is 9 cm.
If the GCF of 36 and ‘b’ is 9, and the LCM is 324. Find ‘b’.
The value of ‘b’ is 81.
GCF × LCM = product of the numbers
9 × 324 = 36 × b
2916 = 36b
b = 2916 ÷ 36 = 81
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.