149 LearnersLast updated on May 26th, 2025
LCM of 2,5 and 7
The meaning of least common factor (LCM) is to find the smallest number that divides any two integers evenly. LCM is used mainly in fractions to find a common number for both the integers. We use LCM for solving problems, lining up cycles or even synchronizing of events, also to schedule tasks in everyday life.
What is the LCM of 2,5 and 7?
We use LCM of 2,5 and 7 to find the smallest number that divides both the numbers equally. The smallest positive number is the number that divides both numbers equally, is 70 without leaving any remainder. LCM is used mainly in fractions to find a common number for both the integers.
How to find the LCM of 2,5 and 7?
The LCM of 2,5 and 7 can be found by the following methods like division method, listing multiples, prime factorization.
LCM of 2,5 and 7 using Division method:
In division method, we divide both the numbers, we begin with dividing side by side the smallest number. We continue dividing until we get a common number that divides both the numbers equally. It makes it easier for the children to focus on prime factors and identify them.
- 2 divides 2, not 5 and 7
- 5 divides 5,not 2 and 7
- 7 divides 7, not 2 and 5.
Now multiply the divisors : 2×5×7=70 which is the LCM.
LCM of 2,5 and 7 using Listing multiples:
Step 1: Start by listing multiples of both the numbers separately:
Multiples of 2 are 2,4,6,8,10,12,14,16,18,20…..70
Multiples of 5 are 5,10,15,20,25,30,35,40,45,50…..70
Multiples of 7 are 7,14,21,28,35,42,49,56,63,70
Step 2: The least common factor from the list is 70. Therefore, the LCM of 2,5 and 7 is 70.
LCM of 2,5 and 7 using Prime factorization:
Step 1:We part the numbers into factors:
Factor of 2: 2
Factors of 5: 5
Factors of 7:7
Step 2:Take the powers of both the numbers and multiply together:
LCM=2x5x7=70.
Common Mistakes and How to Avoid Them in LCM of 2,5 and 7
Common Mistakes and How to Avoid Them in LCM of 2,5 and 7
Mistake 1
Stopping the division method way too soon.
Students sometimes stop dividing very soon, when they are not able to divide both the numbers with the same number. For example, we can divide14 by 2, but 15 isn't divisible by 2. To continue the dividing method until all the factors are found. The students should continue dividing until they find the common number that divides both the integers.
LCM of 2,5 and 7 Examples
Problem 1
If the LCM of 24 and x is 72, what is the possible value of x?
Answer : x =9
Explanation
72= 24 x x / GCD(24,x).
24= 2×2×2×3, so x should contain missing factor 3.
x= 3×3=9.
Problem 2
If the LCM of 12 and a number x is 48, find the possible values of x.
Answer: x=4.
Explanation
LCM (12,x)=48
12=2x2x3
Factors 0f 48=2×2×2×2x3
Missing factor : 22=4
So x=4.
Problem 3
Verify if LCM (15,20) x GCD (15,20)
LCM(15,20) x GCD(15,20) = 300
Explanation
LCM(15,20)=60
GCD(15,20)=5
60 × 5=300
Problem 4
Find the LCM of 24, 36, and 60 using prime factorization.
LCM of 24,36 and 60 = 360
Explanation
LCM of 24,36 and 60
Prime factors of 24: 23×3
Prime factors of 36: 22×32
Prime factors of 60=22 × 3 × 5
LCM =23 × 32 × 5 =360
Problem 5
The LCM of x and 28 is 84. What is x?
Answer: x=3.
Explanation
Factors of 28: 22 × 7
Factors of 84: 2x2×3x7.
X should include the missing factor 3, so x=3.
FAQs on LCM of 2,5 and 7
1. What is the LCM of 5 and 7?
2.Why should we need GCF?
3.How do you find an LCD?
4.Which fraction is equivalent?
5.In mathematics, what is reciprocal?
6.How can children in Qatar use numbers in everyday life to understand LCM of 2,5 and 7?
7.What are some fun ways kids in Qatar can practice LCM of 2,5 and 7 with numbers?
8.What role do numbers and LCM of 2,5 and 7 play in helping children in Qatar develop problem-solving skills?
9.How can families in Qatar create number-rich environments to improve LCM of 2,5 and 7 skills?
Important glossaries on the LCM of 2,5 and 7
- Prime Factor: A natural number or whole number which has factors that are 1 and itself. For Example, 3 is a prime number.
- Prime Factorization: The process of breaking down a number into its prime factors is called Prime Factorization. For example, the factorization of 14 is 2×7.
- Co-prime numbers: numbers which have the only positive divisor of them both as 1. For example, 6 and 7.
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About BrightChamps in Qatar
Hiralee Lalitkumar Makwana
About the Author
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.
Fun Fact
: She loves to read number jokes and games.
