13.3 Estimating square roots
Estimating square roots
To estimate square roots which are not perfect squares without using a calculator, we need to know the perfect square numbers well. We will first put the number inside the square root sign in the middle of a number line, and then find the two closest perfect square numbers on its left and right hand side to make the best estimation.
Basic concepts:
 Divisibility rules
 Introduction to exponents
Lessons

1.
Estimate the values to two decimal places. Check the answers with a calculator.

3.
Alice has baked a square cake that has a top surface area of 335 $c{m^2}$. She has a rectangular box that has a width of 20 cm and length of 27 cm.