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SAI International School

Grade -VII

Mathematics

Chapter- 13: EXPONENTS AND POWERS

Lesson Note:2

SUB TOPIC: Standard Foorm of Exponents, Uses of Exponents,
Comparison of Quantities

Exponents: Exponents are used to express large numbers in shorter form to
make them easy to read, understand, compare and operate upon

Standard Form: Any number can be expressed as a decimal number between
1.0 and 10.0 (including 1.0) multiplied by a power of 10. Such form of a number
is called its standard form or scientific Notation.

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

Uses of Exponents

Inter Conversion between Standard and Normal Forms

Very large numbers or very small numbers can be represented in the standard
form with the help of exponents.
Example: 150,000,000,000, :

> Decimal place towards the left.

Since the decimal is moved 11 places till it is placed between 1 and 5, our standard
11
form representation of the large number will be 1.5×10
If it is a very small number like 0.000007, we need to move the decimal places to the
right in-order to represent the number in its standard form. When being shifted to the
right, the exponent will be negative.