### Exponents and Powers - Revision Notes

CBSE Class 8 Mathematics

Revision Notes

Chapter – 12

Exponents and Powers

Revision Notes

Chapter – 12

Exponents and Powers

- Numbers with exponents obey the following laws of exponents.

(a)

(b)

(c)

(d)

(e)

(f) - Very small numbers can be expressed in standard form using negative exponents.
- Use of Exponents to Express Small Number in Standard form:

(i) Very large and very small numbers can be expressed in standard form.

(ii) Standard form is also called scientific notation form.

(iii) A number written as is said to be in standard form if m is a decimal number such that and n is either a positive or a negative integer. - Examples: 150,000,000,000 = 1.5 x 1011.
- Exponential notation is a powerful way to express repeated multiplication of the same number. For any non-zero rational number ‘a’ and a natural number n, the product a x a x a x ........... x a(n times) = an.

It is known as the nth power of ‘a’ and is read as ‘a’ raised to the power n’. The rational number a is called the base and n is called exponent.