# Exponents and Powers

**Exercise 1**

**1.** Evaluate:

(i) 3^{-2} (ii) (–4)^{2 }(iii)

**2. ** Simplify and express the result in power notation with positive exponent:

**3. ** Find the value of:

**4. **Evaluate:

**5.** Find the value of m for which 5^{m} ÷ 5^{-3} = 5^{5}.

6. Evaluate:

**7. ** Simplify:

**Exercise 2**

**8. ** Express the following numbers in standard form:

(i) 0.0000000000085 (ii) 0.00000000000942

(iii) 6020000000000000 (iv) 0.00000000837

(v) 31860000000

**9.** Express the following numbers in usual form:

(i) 3.02 × 10^{-6} (ii) 4.5 × 10^{4} (iii) 3 × 10^{-8}

(iv) 1.0001 × 10^{9} (v) 5.8 × 10^{12} (vi) 3.61492 × 10^{6}

**10.**Express the number appearing in the following statements in standard form:

(ii) Charge of an electron is 0.000,000,000,000,000,000,16 coulomb.

(iii) Size of a bacteria is 0.0000005 m.

(iv) Size of a plant cell is 0.00001275 m.

(v) Thickness if a thick paper is 0.07 mm.

**11. ** In a stack there are 5 books each of thickness 20 mm and 5 paper sheets each of thickness 0.016 mm. What is the total thickness of the stack?