RBSE Class 7 Maths Notes Chapter 13 Exponents and Powers

These comprehensive RBSE Class 7 Maths Notes Chapter 13 Exponents and Powers will give a brief overview of all the concepts.

RBSE Class 7 Maths Chapter 13 Notes Exponents and Powers

→ We can write large numbers in a shorter form using exponents. Observe 10,000 = 10 × 10 × 10 × 10 = 10⁴
The short notation 104 stands for the product 10 × 10 × 10 × 10. Here ‘10’ is called the base and ‘4’ the exponent. The number 10⁴ is read as 10 rajsed to the power 4 or simply as fourth power of 10.

→ 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.

→ Numbers in the exponential form obey certain laws, which are :
For any non-zero integers a and b and whole numbers m and n;
(a) a^m × aⁿ = a^m+n
(b) a^m ÷ aⁿ = a^m-n, m > n
(c) (a^m)ⁿ = a^mn
(d) a^m × b^m = (ab)^m
(e) a^m ÷ bⁿ = \left(\frac{a}{b}\right)^{m}
(f) a° = 1
(-1)^{even number} = 1
(-1)^{odd number} = - 1

→ 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 a form of a number is called its standard form or scientific notation.