Suppose we have number like

8.jpg

Here,

  Exponent(Power) is negative

 

It means

  10 − 2 = 1/10 2

= 1/100

= 001/100

= 0.01

∴ 10 −2 = 0.01

 

  10 − 4 = 1/10 4

 = 1/10000

 = 00001/10000

= 0.0001

 

  2 − 4 = 1/2 4

         = 1/(2 × 2 × 2 × 2)

         = 1/(4 × 4)

         = 1/16

 

  3 − 2 = 1/3 2

= 1/(3 × 3)

= 1/9

 

  6 − 3 = 1/6 3

 = 1/(6 × 6 × 6)

 = 1/(36 × 6)

 = 1/216

 

  (1/3) -2 = 1 -2 /3 -2

  = 1/3 -2

  = 3 2

  = 9

 

(1/ 10) - 4 = 1 -4 /10 -4

   = 1/10 -4

   = 10 4

   = 10000

 

  ( 2 / 3) - 3 = 2 -3 /3 -3

   = ((1/2 3 ))/((1/3 3 ) )

   = 1/2 3  ÷ 1/3 3

   = 1/2 3  × 3 3 /1

   = 3 3 /2 3

   = (3 × 3 × 3)/(2 × 2 × 2)

  = (9 × 3)/(4 × 2)

  = 27/8

  1. Chapter 13 Class 7 Exponents and Powers
  2. Concept wise

About the Author

Davneet Singh's photo - Teacher, Computer Engineer, Marketer
Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.