Least Common Multiple

Least Common Multiple (Activity)

Objectives: Students will be able to understand the meaning and how to find LCM.

Questions:

• How do you define multiples?
• Find the multiples of 3, 5, 7?

Materials Required:

• Meter tape/rod.
• Small Circular Boards.
• Chalk

Activity:

Teacher tells a story to students.

(Once there was running a completion between the animals in a forest. In that completion the lion win the race. Deer, the friend of lion was very happy for the win of his friend lion. He congratulate his friend for his success, the lion also impress with the running of deer. A monkey came to them and told them that you both should not be both friend as you have different speed. The monkey blames the deer for his running speed. The lion told the monkey it’s true that we have different speed but we can meet at particular points in out running. The monkey said no never, you both cannot meet at any point while running. (Hints: the lion and deer jumps at a distance of 3 foot and 2 foot respectively).

 

What do you think, whether the lion and deer meet at any point or not?

Collect the response of students.

Lets us play an activity to clarify our doubt. Teacher takes all students to veranda.

Teacher select two students one named as Lion and the Deer. Asked the students named as Lion and Deer to jump at 3 foot and 2 foot respectively. With the support of meter tape he draws a line and marked 1 feet distance in that line. Instruct the two students to walk side the line with the given distance. He instruct the lion to wait after each step whether his friend can reach at that point or not. They have to put the circular card board on that point, where both meet each other.

  

After walking on the side of the line teacher asked the students..

·         Which are the points where the lion meets?

·         Which are the points where the deer meets?

·         Which are the points at which both lion and deer touches?

So the multiples of 3 are:   3, 6, 9, 12, 15, 18 .....  (Steps covered by lion)

The multiples of 2 are      : 2, 4, 6, 8, 10, 12, 14, 16, 18.....  (Steps covered by lion)

The common multiples are: 6, 13, 18....

The least of the common multiples is: 6

The LCM is named as Least Common Multiples.