A whole number is a perfect square if it can be expressed as the product of two equal whole numbers. For example, $$9$$ is a perfect square since $$9= 3\times 3$$. How many perfect squares are greater than $$0$$ and less than $$1000$$? 
Overseas Competition->Knowledge Point->Number Theory Modules->Perfect Square Numbers->Basic Applications of Square Numbers
A whole number is a perfect square if it is the product of two equal whole numbers. Thus, $$1\times1$$ and $$2\times 2$$ and $$3\times 3$$ and $$4\times 4$$ are perfect squares. Continue until the product is bigger than $$1000: 30\times 30 = 900$$; $$31\times 31 = 961$$; $$32\times 32 = 1024$$ (too big). 