Class 7 · Chapter 13

Exponents and Powers

Laws of exponents; expressing large numbers in standard form.

Watch this chapter

Read the full chapter

Tip: open the NCERT PDF for the original chapter text alongside the notes here.

Detailed theory

a^n

means

a

multiplied by itself

n

times.

a

is the base,

n

is the exponent. E.g.

2^5 = 32

Key concepts & formulas

a^m \cdot a^n = a^{m+n}

\dfrac{a^m}{a^n} = a^{m-n}

(a^m)^n = a^{mn}

a^0 = 1

(for

a\ne 0

a^{-n} = \dfrac{1}{a^n}