What Have We Discussed?

Very large numbers are difficult to read, understand, compare and operate upon. To make all these easier, we use , converting many of the large numbers in a shorter form.

2. The following are exponential forms of some numbers:

10,0=104 (read as 10 raised to the of 4)

243 = 3 , 128 = 2.

Here, 10, 3 and 2 are the , whereas 4, 5 and 7 are their respective .

We also say, 10,000 is the th power of 10, 243 is the th power of 3, etc.

Numbers in exponential form obey certain laws called law of exponents, which are:

For any non-zero integers a and b and whole numbers m and n,

(a) am×an= a.

(b) am÷an= a , m > n

(d) am×bm= ab.

(e) am÷bm= ab.

(f) a0=

(g) −1evennumber=

(h) −1oddnumber=

Exponents and Powers