Learn Class 8 Math - Exponents and Powers

A number multiplied by a power of the number gives a number's multiplicative power. The form of the formula is ab. The variables a and b indicate how many times we will need to multiply a to arrive at our result. The base is A, and the exponent is B.

For example, Consider 9³. Here, 9³ indicates that we need to multiply the base number 9 by three to obtain the answer, which is 27.

Powers with Negative Exponents

Any non-integer power with a negative exponent is essentially its reciprocal.

When there is an exponent -b on an integer a, a-b = 1ab.

Exponential form refers to the operation of multiplying the number by its exponents.

This is how it is written:

  • For example, 10 represents the base, 9 represents the exponent, and the complete number represents the power.
  • The number 10 raised to power 9 is pronounced as 10. Positive or negative exponents are both possible.

Hence, if we multiply 10 by nine we get: 10 * 10 * 10 * 10 * 10 * 10 * 10 * 10 * 10.

Learning Videos for 8th Grade Math - Exponents and Powers

Exponents and Powers Sample Questions for Class 8

Question 1

Which of the following fractions most closely approximates the value of pi?
A. 7/21
B. 7/22
C. 21/7
D. 22/7

Question 2

Simplify 4^3 * 4^5 and write your answer as a power.
A. 8^8
B. 4^15
C. 16^5
D. 16^8

Question 3

The following scatterplot is a great example of linear association.
A. True
B. False

Question 4

Given that x=2,y=-3, and z=-1, find the value of the following: (5xyz)^2-5(x+yz)^2.
A. 895
B. 775
C. 825
D. 695

Question 5

The value of sqrt99 falls between 9 and 10.
A. True
B. False