Exponents and Powers - Worksheets

 CBSE Worksheet-1

CLASS –VII Mathematics (Exponents and Powers)

Choose correct option in questions 1 to 4.

  1. Find the value of (−9)3×(−4)2.
    a) -11664
    b) 36
    c) 5
    d) 25
  2. Simplify: 7x×72
    a) 7x+3
    b) 7x+2
    c) 72x
    d) 7x-2
  3. Which is greatest among the following?
    a) 82
    b) 43
    c) 28
    d) 32
  4. Find the value of (60−20)×(60+20).
    a) 2
    b) 1
    c)3
    d) 0
  5. In (-9)4, the base is _______ and the exponent is 4.
  6. (-1)4 is equal to ____.
  7. (ax)y = _____
  8. What should be added to 2y2 - 4yz - 2z2 to get y2 - 2yz - z2.
  9. Express the following numbers in the standard form.
    a) 5,223,000,000
    b) 256,000,000
  10. Simplify and write the answer in exponentialform.
    a) 37÷ 34
    b) 58÷ 54
  11. Find m when (29)3×(29)−6=(29)2m−1

CBSE Worksheet-1
CLASS –VII Mathematics (Exponents and Powers)
Answer key

  1. a 
  2. b ; { 7x x 72 = 7x+2 ( when bases are same and there is a sign of multiplication in between then the exponents get added) }
  3. c ; { 82 = 64 , 43 = 64, 28 = 256, 32 = 9 }
  4. a; { (60 - 20) × (60 + 20) = ( 1 - 1 ) x ( 1 + 1) = (0) x ( 2) = 0 ( any base number with exponent 0 is equal to 1) }
  5. -9
  6. 1
  7. axy ; { in this case exponents will get multiplied }
  8. (y2 - 2yz - z2 ) - ( 2y2 - 4yz - 2z2)
    =  y2 - 2yz - z2 - 2y2 +4yz +2z2
    = - y2 + 2yz + z2
  9. a. 5.223 x 109
    b) 2.56 x 108 
  10. a) 33 ; { 3 7-4 when the bases are same and there is a sign of division in between then the exonents get subtracted }
    b) 54 ;{ 58-4 when the bases are same and there is a sign of division in between then the exonents get subtracted }
  11. (29)3+(−6)=(29)2m−1
    =(29)−3=(29)2m−1
    ⇒ 2m - 1 = -3
    2m = -3 + 1
    2m = -2
    m=−22
    m = -1