196 LearnersLast updated on May 26th, 2025
LCM of 5 and 7
LCM is a common multiple, the smallest value between the numbers 5 and 7. Did you know? We apply LCM unknowingly in everyday situations like setting alarms and to synchronize traffic lights and when making music.
What is the LCM of 5 and 7?
The LCM of 5 and 7. We can find the LCM using the Listing multiples method, the prime factorization method and the long division method. These are explained below.
LCM of 5 and 7 using the Listing Multiples Method
Step 1: Write down the multiples of the numbers. Don’t stop too early.
Multiples of 5 = 5,10,15,20,25,30,35…
Multiples of 7 = 7, 14,21,28,35,…
Step 2: Find the smallest number common between the written multiples of 5 and 7
The smallest common multiple is 35
Thus, LCM(5,7) = 35
LCM of 5 and 7 using the Prime Factorization Method
Step 1: factorize the numbers into its prime factors
5 = 5×1
7 = 7×1
Step 2: find the highest powers of the factors of 5 and 7
Step 3: Multiply the highest powers
LCM(5,7) = 35
LCM of 5 and 7 using the Division Method
- Write the numbers 5,7 in a row
- Divide them by their common prime factors, if there is one
- Carry forward the numbers that are left undivided by the previously chosen factor
- Continue dividing until the remainder is ‘1’
- Multiply the divisors to find the LCM
- LCM(5,7) = 35
Common Mistakes and how to avoid them while finding the LCM of 5 and 7
Listed here are a few mistakes that one can commit when trying to find the LCM of the numbers 3 and 8. Try to avoid them.
Mistake 1
Listing incorrect multiples
If the LCM of given numbers is 35, double-check that the number appears on the list of both 5 and 7.
LCM of 5 and 7, examples
Problem 1
In a neighborhood park, the fountain show is turned on every 5 minutes, and the light show every 7 minutes. If both the shows are turned on at the same time, when will they next be turned on together again?
The LCM of 5 and 7.
Explanation
Both the shows will turn on at the same time in 35 minutes. The LCM of 5 and 7 is 35, which is the smallest common time interval for the given digits.
Problem 2
The LCM of 5 and 7 is 35. If 35 represents 70% of a certain number, what is the original number?
Let the original number be x.
70% of x is equal to 35:
0.7x=35
Solving for x,
x=35/0.7=50
Explanation
Thus, the original number is 50.
Problem 3
Verify the relationship between the LCM and GCD of 5 and 7 using the formula: LCM(a,b)×GCD(a,b)=a×b
For a=5 and b=7:
LCM(5,7)=35
GCD(5,7)=1 (since 5 and 7 are relatively prime).
According to the formula:
35×1=5×7
Explanation
Both sides equal 35, verifying that the relationship holds.
FAQs on LCM of 5 and 7
1. What are the multiples of 5 and 7?
2.What is the LCM of 5,7 and 9?
3. What is the GCF of 5 and 7?
4. What is the LCM of 3,5 and 7 ?
5.What is the LCM of 8 and 5?
6.How can children in United States use numbers in everyday life to understand LCM of 5 and 7?
7.What are some fun ways kids in United States can practice LCM of 5 and 7 with numbers?
8.What role do numbers and LCM of 5 and 7 play in helping children in United States develop problem-solving skills?
9.How can families in United States create number-rich environments to improve LCM of 5 and 7 skills?
Important glossaries for the LCM of 5 and 7
- Multiple — product of a number and a natural integer
- Prime factor — number one gets after prime factorization any given number
- Prime factorization — the process of breaking the number into its prime factors.
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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
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