A student need to practice maths problems. Its helps in developing problem solving skills. The problems shall not be (i) too simple, (ii) too difficult or (iii) too many. Simple problems are boring, difficult problems discourages (at times), and too many problems don't leave time for fun.

I selected following problems on exponents for my son studying in class 8.

- Evaluate $\left(\frac{-3}{4}\right)^{-4}$.
- Evaluate $\left(\frac{8}{5}\right)^{-2}\times \left(\frac{8}{5}\right)^2$.
- Evaluate $\left(\frac{-2}{7}\right)^{-4}\times\left(\frac{-5}{7}\right)^2$.
- Evaluate $\left\{\left(\frac{-3}{2}\right)^2\right\}^{-3}$.
- By what number should $\left(\frac{1}{2}\right)^{-1}$ be multiplied so that the product is $\left(\frac{-5}{4}\right)^{-1}$?
- By what number should $\left(\frac{-3}{2}\right)^{-3}$ be divided so that the quotient is $\left(\frac{9}{4}\right)^{-2}$?
- If $5^{2x+1} \div 25=125$, find the value of $x$.