Class 8 Maths – Chapter 12
Exponents & Powers
STEP 5: Application Notes (Exam Focus)
Exponents & Powers
STEP 5: Application Notes (Exam Focus)
1. Using Laws of Exponents in Problems
Always check whether the bases are same or different before applying laws.
Example:
2³ × 2² = 2⁵ (Add powers because base is same)
Always check whether the bases are same or different before applying laws.
Example:
2³ × 2² = 2⁵ (Add powers because base is same)
2. Simplifying Expressions
Apply laws step by step and write each step clearly.
Example:
(3² × 3³) ÷ 3²
= 3⁵ ÷ 3²
= 3³
Apply laws step by step and write each step clearly.
Example:
(3² × 3³) ÷ 3²
= 3⁵ ÷ 3²
= 3³
3. Solving Problems with Zero & Negative Powers
Remember:
a⁰ = 1
a⁻ⁿ = 1 / aⁿ
Example:
5⁰ + 2⁻¹ = 1 + 1/2 = 3/2
Remember:
a⁰ = 1
a⁻ⁿ = 1 / aⁿ
Example:
5⁰ + 2⁻¹ = 1 + 1/2 = 3/2
4. Writing Large Numbers using Powers of 10
Powers of 10 help us represent very big numbers easily.
Example:
1,000,000 = 10⁶
Powers of 10 help us represent very big numbers easily.
Example:
1,000,000 = 10⁶
⭐ Exam Tip:
• Write laws first
• Solve step by step
• Neat steps = full marks
• Write laws first
• Solve step by step
• Neat steps = full marks
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