Math Story : Least Common Multiple (LCM)

All About 3, 6 And 8 Day

It is a beautiful morning of a new month. Uncle Math has his entire month planned. Beep! Beep! Suddenly he receives a message.

“It is bad news! Atriho Boss, Acirho Boss and Asquarho Boss are going to attack Samper town. When and how is still unclear. I will keep you posted. Just be ready”, said the message. Uncle Math goes blank after hearing this. What will they do now? How long can they fight these villains? He decides to call the kids and plan things accordingly.

Uncle Math and the kids sit together to plan their next steps. Beep! Beep! They receive another message. “Haha! So you thought your friends will give you the information about the attack! Let me only tell you. We will attack you on the 3rd day, 6th day and 8th day from today! We will come together and win this time. Stop us if you can! Haha!” said the message.

“That was Atriho Boss! And they are coming back even stronger”, says Uncle Math. Everybody is stressed. What will they do now? What will be their strategy?

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It is the 3rd day! The attack might happen anytime now. Everybody is ready to face them.

It’s a tense morning and everybody is ready to face them. They wait, wait and wait. But nobody comes. Soon the day gets over. Why they didn’t show up? Is this a trap? Everybody decides to wait for the sixth day. 

It is the 6th day. “We are ready!” says Squarho. They wait, wait and wait. But nobody comes again. “Let us not lose focus. They might have a different plan and we need to be attentive all the time”, says Triho. 

They wait, wait and wait. Yet nobody comes. “I will go and look behind. What if they attack from there,” says Squarho. Cirho agrees and joins him to check on the other sides.

“No trace of them”, say Squarho and Cirho. Everybody is confused now!

It is day 8! “They will surely turn up today! Be ready guys”, says Cirha. They wait, wait and wait. Do you think Atriho Boss and his friends will come today?

As expected, nobody turns up. “This is so unusual! Something is not right here! How can they inform and don’t turn up”, says Cirha. Everybody finds this very fishy. What do you think the boss villains are up to? 

“We will come together. They said we will come together. Is this a hint?” whispers Uncle Math. He is thinking hard and trying to make connections. Will he be able to solve this?

After some deep thinking, Uncle Math is surprised. It looks like he has decoded their plan. “My goodness! They played with us! They were not planning to attack on days 3, 6 or 8. They will come together on the 24th day! This is going to be massive”, he panics.

“What? What makes you say so?” wonders Triho. “They said they will come together. They didn’t turn up on days 3, 6 and 8! Doesn’t that mean they were fooling us so that they could come back stronger”, explains Uncle Math. “But why day 24 only? Is there some pattern?” asks Cirha.

“Yes! They are following a pattern. They are using LCM!” says Uncle Math. LCM? Another alien word? What do you think this means?

LCM stands for least common multiple. It is the smallest number that is a multiple of each of two or more numbers. LCM will help us know when all the three would come together and attack us”, adds Uncle math. He quickly runs to get something.

“Meet Mr LCM! He will help us here,” he says and inputs 3, 6 and 8 into it. Mr LCM displays 24 as the answer. “I don’t understand”, says Cirho. Uncle Math quickly takes out the attacked digital pen and starts writing something on Mr LCM.

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Uncle Math 9 to 11 Years App Banner

When we multiply a number, with itself or other numbers, the result is nothing but the multiple of that number. “Can you tell me the multiples of 3?” asks Uncle Math. “3,6,9,12,15,18,21.24,27,30” answers Cirho. He writes them on the board. Similarly, he asks Squarho and Triho to give multiples of 6 and 8. Can you write the multiples of 6 and 8 too?

Yes! 6,12,18,24,30,36,42,48,54,60 are the multiples of 6. And 8,16,24,32,40,48,56,64,72,80 are the multiples of 8. “Observe carefully and identify the smallest number that is multiple of all the three”, asks Uncle Math. “24!” says Cirha after observing all the three.

Now the kids understand that on day 24, all the three villains will attack them. “If one of them attacking us can cause so much damage, then imagine how bad it will be when three of them come together”, says Squarho. Everybody is stressed.

“Facing them alone only a tough task. If they come together, it is going to be a disaster. We won’t be able to defeat them alone. We need more people”, says Cirha. “Yes! How about we take the help of the citizens of Samper town? The more we are, the stronger our team would be”, suggest Triho. Uncle Math likes the idea. The kids decide to launch a campaign seeking help for their city.

More and more people agree to join them in their fight against the boss villains.

“It is our town. We will never let it down”, says everyone. They start training the citizens. It looks like the boss villains will go empty-handed this time. What do you think?

It is day 24. As expected all the three boss villains are here today. They are attacking from three different sides assuming that the people of Samper town must not be ready for the war today. Haha! They will know soon.

Asquarho Boss rushes with his army to attack from the left side. To his surprise, there were people already, waiting for him. Cirha is leading them. She guides everyone to attack. “It is our town. We will never let it down”, says everyone and runs to attack.

 Smash! Boo! Bang! Asquarho Boss and his army run to save themselves.

On the other side, Acirho Boss attacks from the right. “It is our town. We will never let it down”, says Cirho and his team. They attack back stronger. Acirho Boss could not handle them. He runs to save himself too. 

But the battle is not over yet. Atriho Boss holds the larger part of his army and is attacking from the front. Triho, Squarho and Uncle Math are waiting with their team to welcome him.

Soon the news of Acirho Boss and Asquarho boss running away to save themselves reaches Atriho. He is furious! “You are dead today”, he says and attacks Triho. His army attacks others. Both the teams are stringer, who will win now?

Triho bravely fights and defeats Atriho Boss. Looking at this, his army surrenders too. “Promise us, you will never return to Smaper town”, says Triho. Atriho Boss agrees and asks for his life in return.

Finally, all the boss villains run away to save themselves. Samper Town is safe. “It is our town. We will never let it down”, says everyone. It is time for celebration. A smart strategy, Mr LCM and a strong determination. Of course, sounds like a perfect formula for victory.

We Learnt That…

  • LCM stands for least common multiple. 
  • It is the smallest number that is a multiple of each of two or more numbers. 
  • LCM is used when in case of repetition, to predict when will the same thing happen again.
  • It is important to understand the importance of a good community and seek their help in need.

Let’s Discuss

  • Why was Uncle Math stressed?
  • What did Atriho Boss say?
  • How did the boss villains fool us?
  • What helped us predict the plan of boss villains? 
  • What is LCM? Explain with an example.

Please refer this guide by Fun2Do Labs for teaching LCM to kids :