Untitled Lesson

​Factors and Multiples
Lesson -3

Learning Objective

To find the LCM of
2 or more numbers
and apply in real
life situations.

To find the LCM of 2 or more numbers.

UAE Connect
:In our school there are three different
bus routes to Ajman,to Sharjah,to Dubai. Each route has a
different time interval between bus arrivals at a given stop, and
these time intervals are not necessarily the same. For instance :Bus Route A arrives every 15 minutes.
Bus Route B arrives every 20 minutes.
Bus Route C arrives every 30 minutes.

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The school administrators want to find the least common
multiple (LCM) of these time intervals to create a schedule that
ensures the buses meet at the school at the same time. This way,
students from different bus routes can arrive and depart
together, minimizing waiting times and ensuring efficient
transportation.

� In healthcare, precise medication administration schedules are essential for
patient well-being. LCM comes into play when
determining dosage intervals, especially for
medications with different dosing
frequencies. Accurate calculations of LCM
help healthcare professionals establish safe
and effective medication regimens, ensuring
optimal patient care

Real life connect:

Success Criteria

can find the prime
factorization of numbers up to a certain range

will be proficient in finding
prime factors for larger
numbers and hence find
LCM.

will be able to apply the
concept of LCM in solving
real life problems.

Keywords

Prime factors

Division method

Factor tree method

Common factors

• Prime Factors

• Common Factors

• Division Method

• Factor Tree

LCM -The least number that is a multiple of given numbers.

LCM of 3 and 5

Multiples of 3----  3,6,9,12,15,18,21,24,27,30,33,…………

Multiples of 5 ----5,10,15,20,25,30,35,40,45,50,55,…….

  common multiples--- 15, 30………

LEAST NUMBER---15( LCM )

​Vocabulary

​ LCM BY
PRIME FACTORISATION

LCM= 2 X 3 X 5 X2 X
3

Write prime factorization of each numbers.
[ can use factor tree or division method]

Multiply all the common factors along with
any remaining prime factors from each
number.

To find the LCM of 2 or more numbers.

What about LCM of more
than 2 numbers ?

Task 2
Athul plays a football match every 4th day and Rahu on every 6th-day .Today they both went for their matches
.When will they again have their
matches on the same day

Task 1
FIND LCM of10 and 20

Task 3
Find Lcm of 30 ,60 and 15

Critical thinking
questions
The number of books in Ali’s collection is divisible by 2,4,5 and 10.He has more than 11 books and fewer than 25 books. How many books does he has ?

� Meghan's cycles around a circular park in 9 mints.Rahul cycles around the same in 12 mints.They start cycling from the same point at the same time. After how much time will they meet again at the starting point?

AOL

PLENARY

If you have a group of friends who areavailable every 4 days and another
group who can meet every 5 days,
when is the next time everyone can meet together?

� Find the LCM of 6,12 and 15

� In a school schedule, if one class lasts 45minutes, and another lasts 60 minutes, what
is the least common multiple of these times to
find when both classes end simultaneously?