✨ Daily Math Magic: Relation Between HCF and LCM
Unlock the powerful relation between HCF and LCM using examples, animated number visuals, formula practice and real-life maths situations.
📌 Learning Map
🎯 Learning Objectives
- Understand HCF and LCM.
- Learn the relation between HCF, LCM and two numbers.
- Apply the relation in quick calculations.
- Connect the formula with daily life examples.
🧩 Competencies
- Numerical Skills
- Logical Thinking
- Problem Solving
- Pattern Recognition
📊 Learning Outcomes
- Defines HCF and LCM correctly.
- Uses the formula accurately.
- Finds missing HCF, LCM or number.
- Solves real-life word problems.
🌈 5W-1H + 1U
🔴 What: HCF is the greatest common factor, and LCM is the least common multiple.
🟠Why: They help us simplify fractions, arrange events, divide items equally and solve number problems.
🟡 When: Use HCF for grouping and LCM for repetition or matching cycles.
🟢 Where: Used in timetables, bells, lights, packaging, sharing and arranging objects.
🔵 Who: Students, teachers, shopkeepers, planners and problem solvers use this idea.
🟣 How: For two numbers, HCF × LCM = Product of the two numbers.
⚫ 1U: This relation works for two numbers, not directly for three or more numbers in the same simple form.
🧮 Magical Formula
HCF × LCM = First Number × Second Number
For two numbers a and b:
HCF(a,b) × LCM(a,b) = a × b
Example: Numbers 12 and 18
HCF of 12 and 18 = 6
LCM of 12 and 18 = 36
HCF × LCM = 6 × 36 = 216
12 × 18 = 216, so HCF × LCM = Product of the two numbers.
Quick Trick
If you know any three values among HCF, LCM and two numbers, you can find the fourth.
✨ HCF and LCM Visualizer
Enter two numbers to see their factors, multiples, HCF and LCM.
Factors of First Number
Factors of Second Number
Common Multiples Preview
🔢 Formula Practice Tool
Find LCM
Use: LCM = Product of two numbers ÷ HCF
Find HCF
Use: HCF = Product of two numbers ÷ LCM
Daily Life Example
Two bells ring every 12 minutes and 18 minutes. When will they ring together?
They will ring together after the LCM of 12 and 18 minutes, which is 36 minutes.
✅ HCF-LCM Relation Quiz
Select the correct answer and click submit to check your score.
🧠HOTS Questions
Click each question to reveal the answer.
1. Why is HCF useful for sharing items equally?
HCF gives the greatest possible equal group size without leaving any item.
2. Why is LCM useful for bells, lights or repeated events?
LCM gives the smallest time after which repeating events occur together again.
3. If HCF is small, can LCM be large?
Yes. Numbers with fewer common factors often have a larger LCM.
4. Does HCF × LCM = product work for three numbers directly?
No. This simple relation works directly for two numbers only.
5. How can we find a missing number using HCF and LCM?
Use: Missing number = HCF × LCM ÷ Given number.
