Definition of Least Common Multiple (LCM)
De finition:
A multiple of a number is the product of the number and another whole number. Factors and multiples are closely related.
For example, 9 is a factor of 90, so 90 is a multiple of 9.
De nition:
The least common multiple or lcm of two or more numbers is the lowest number that is a multiple of each of the numbers. One method of nding the least common multiple involves listing the multiples of each number until you nd the rst number that is a multiple of both.
Example Find the least common multiple of 6 and 8.
The first few multiples of 6 are 6 12 18 24 30 36 42 48…
The first few multiples of 8 are 8 16 24 32 40 48 56 64…
Read more
GCD: Problem Set and Answer
Math Problem Set
1. Sam was buying hot dogs and hot dog buns for a backyard barbeque. Hot Dogs come in packs of 16, but buns come in packs of 12. How many packs of each will Sam have to buy so that there are no hot dogs or buns left over?
2. A florist has 72 roses, 84 tulips and 48 orchids that she wants to use to create bouquets. What is the largest number of identical bouquets she can put together without having any owers left over?
3. Three alarm clocks are set o at the same time. If the rst one beeps every 9
seconds, the second one beeps every 12 seconds and the third one beeps every 15 seconds, how long will it be until they beep at the same time?
4. Vince has three pieces of rope with lengths of 300 cm, 312 cm and 396 cm. He wants to cut the three pieces of rope into smaller pieces of equal length with none left over.
(a) What is the greatest possible length of each of the smaller pieces of rope?
(b) How many of the smaller pieces of rope will he have altogether?
Read more
Greatest Common Divisor
Find the greatest common divisor of the following numbers using factor trees.
1) 420 and 168
