5 min read
Number Lcds
x/2 + x/5 = 7x/10. LCD 10. x-22 + x+109 uses LCD 18: 9(x-2)+2(x+10) all over 18 = 11x+1618.
Choose Your Level
Number Lcds
What is it?
x/2 + x/5 = 7x/10. LCD 10. x-22 + x+109 uses LCD 18: 9(x-2)+2(x+10) all over 18 = 11x+1618.
In simple words
- x/2 + x/5 = 7x/10.
- LCM of bottoms
- LCD from factors
- then combine tops
Important terms
Number Lcds: x/2 + x/5 = 7x/10. LCD 10. x-22 + x+109 uses LCD 18: 9(x-2)+2(x+10) all over 18 = 11x+1618.
What you should learn
- Define and explain number lcds.
- Apply number lcds to a focused FBISE question.
- Check the answer for correct terms, evidence, working, and units.
Examples
- LCM of bottoms
- LCD from factors
- then combine tops
CORE UNDERSTANDING
x/2 + x/5 = 7x/10. LCD 10. x-22 + x+109 uses LCD 18: 9(x-2)+2(x+10) all over 18 = 11x+1618.
EXAM APPLICATION
State the correct term, connect it to the chapter rule or evidence, and use a clear example or calculation.
Recommended for Class 10
Full school-level explanation
x/2 + x/5 = 7x/10. LCD 10. x-22 + x+109 uses LCD 18: 9(x-2)+2(x+10) all over 18 = 11x+1618.
Learn the idea, then use it:
WHAT — NUMBER LCDS
x/2 + x/5 = 7x/10. LCD 10. x-22 + x+109 uses LCD 18: 9(x-2)+2(x+10) all over 18 = 11x+1618.
HOW — Use the idea
Identify what is given, select this topic's rule or evidence, apply it one step at a time, and check the result.
CORE UNDERSTANDING
x/2 + x/5 = 7x/10. LCD 10. x-22 + x+109 uses LCD 18: 9(x-2)+2(x+10) all over 18 = 11x+1618.
Remember
- LCM of bottoms
- LCD from factors
- then combine tops
Examples
- LCM of bottoms
- LCD from factors
- then combine tops
- NUMBER LCDS: x/2 + x/5 = 7x/10. LCD 10. x-22 + x+109 uses LCD 18: 9(x-2)+2(x+10) all over 18 = 11x+1618.
EXAM APPLICATION
State the correct term, connect it to the chapter rule or evidence, and use a clear example or calculation.
Remember
- correct term
- chapter link
- clear application
Examples
- Define first
- Show the rule or evidence
- Check units, labels, and conclusion
Remember
- LCM of bottoms
- LCD from factors
- then combine tops
- keep the ideas separate
- LCM of bottoms
- LCD from factors
- then combine tops
- correct term
Deeper understanding
Go beyond memorising Number Lcds. Connect the definition to reasons, relationships, exceptions, and exam wording.
Common mistakes
Exam focus
Core Idea
Key Points
Simple Check
How to Answer
Exam focus
Quick revision
- LCM of bottoms
- LCD from factors
- then combine tops
- keep the ideas separate
- Number Lcds: x/2 + x/5 = 7x/10. LCD 10. x-22 + x+109 uses LCD 18: 9(x-2)+2(x+10) all over 18 = 11x+1618.
- WHAT — NUMBER LCDS: x/2 + x/5 = 7x/10. LCD 10. x-22 + x+109 uses LCD 18: 9(x-2)+2(x+10) all over 18 = 11x+1618.
Do not merge number lcds with a neighbouring idea that uses a different definition, rule, or method.
For long answers on Number Lcds: define clearly → explain the main parts → give one example → state one exam caution.
Exam Focus
Exam Focus
Important points
- LCM of bottoms
- LCD from factors
- then combine tops
- keep the ideas separate
Important formulas
- LCM of bottoms
- LCD from factors
- then combine tops
Common exam traps
- Do not merge number lcds with a neighbouring idea that uses a different definition, rule, or method.
- Do not invent a formula, fact, unit, or diagram label that the chapter does not support.
Long question structure
Definition → key parts → example → exam caution
Common Mistakes
Common Mistakes
- Mistake
Do not merge number lcds with a neighbouring idea that uses a different definition, rule, or method.
- Mistake
Do not invent a formula, fact, unit, or diagram label that the chapter does not support.
- Mistake
Do not merge number lcds with a neighbouring idea that uses a different definition, rule, or method.
Revision Zone
60-Second Revision
Quick cues from this topic — use them for last-minute revision.
LCM of bottoms
LCD from factors
then combine tops
keep the ideas separate
x/2 + x/5 = 7x/10. LCD 10. x-22 + x+109 uses LCD 18: 9(x-2)+2(x+10) all over 18 = 11x+1618.
- Definition
- x/2 + x/5 = 7x/10. LCD 10. x-22 + x+109 uses LCD 18: 9(x-2)+2(x+10) all over 18 = 11x+1618.
- Example
- LCM of bottoms
- Critical warning
- Do not merge number lcds with a neighbouring idea that uses a different definition, rule, or method.
Did you understand this topic?
Your answer is saved with your learning record. It does not mark the topic as mastered.
Ready to test yourself?
You've completed the learning section.
Exam Practice
Define
Q1. Define Number Lcds.
Explain
Q2. Explain: CORE UNDERSTANDING.
Example
Q3. Give one clear example of Number Lcds and say why it fits.
Mistake
Q4. State one common mistake students make about Number Lcds.
Exam note
Q5. Write a short exam note on Number Lcds: definition, two points, one example.
Sources & References
School-standard facts for Matric and Intermediate. Original explanations — not copied from textbooks.