Class 8 Maths Exponents and Powers Introduction

Introduction:

Writing, reading and comapring the smaller numbers are very

easy as compare to larger numbers.

Ex: 15, 100, 1250, 20000 are small number.

But when we talk about larger number, it is very difficult to read,

understand and compare.

Ex: Distance between Sun and Saturn is 1,433,500,000,000 m and distance

between Saturn and Uranus is 1,439,000,000,000 m.

These are very large numbers and also it is very difficult to read,

write, understand and compare. To

make these numbers easy to read, understand and compare,

we use the concept of exponents.

The concept of exponent makes the represenation of

biggere number easier.

Ex: let a number 10,000

We can write 10,000 = 10 * 10 * 10 * 10 = 104

Here the notation 104 is the shot notation of 10 * 10 * 10 * 10 i.e. 10,000

So, 104 is the exponential form of 10,000

Here 10 is called the base and 4 the exponent. The number 104 is read as 10 raised to the power of 4 or

fourth power of 10.

Again, 1,000 = 10 * 10 * 10 * 10 = 103

So, 103 is the exponent form of 1,000

We can use numbers like 10, 100, 100, etc to write a numbers in expanded form.

Ex: 12534 = 1 * 10000 + 2 * 1000 + 5 * 100 + 3 * 10 + 4 * 1

= 1 * 104 + 2 * 103 + 5 * 102 + 3 * 10 + 4

The numbers which have base other than 10 can also be represented in exponent form.

64 = 2 * 2 * 2 * 2 * 2 * 2 = 26

Here, 2 is the base and 6 is the exponent.

So, any number am is in the form of exponent where a is the base and m is the exponent and we read as

“a raised to power m”.  .