How to find the lowest common multiple (LCM) of two (or more) numbers in maths? Grade 7 maths questions are presented along with detailed solutions. Detailed Solutions and explanations are included.
What is the lowest common multiple (LCM) of two or more whole numbers?
Examples: Find lowest common multiple of the numbers 6 and 8. List the first few multiples of both numbers and stop as soon as you find a common multiple. 1) Multiply 6 by 1, 2, 3,.. to obtain the first few multiples of 6: 6, 12, 18, 24, 30, 36 ... 2) Multiply 8 by 1, 2, 3,.. to obtain the first few multiples of 8: 8, 16, 24,32 ,40 ... Examine the multiples: The lowest common multiple of of 6 and 8 is 24. Method 2: It uses prime factorization may be used for all numbers Examples: Find lowest common multiple (LCM) of the numbers 42 and 60. step 1  The prime factorization of 42 is: 42 = 2 × 3 × 7 step 2  The prime factorization of 60 is: 60 = 2^{ 2} × 3 × 5 step 3  The LCM is given by product of all prime number in the prime factorization with the highest power. A Lowest Common Multiple Calculator (LCM) may be used to check your answers.

More Middle School Maths (Grades 6, 7, 8, 9)  Free Questions and Problems With Answers
More High School Maths (Grades 10, 11 and 12)  Free Questions and Problems With Answers
More Primary Maths (Grades 4 and 5) with Free Questions and Problems With Answers
Home Page