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Question

20 is not a whole number because there is no whole number we can multiply by itself to find a product of 20. That means
20
​
is irrational, so we can only find an approximation of its value. To help us do that, we can find the two perfect squares that 20 is between, and then the two perfect square roots that
20
​
is between. Start by completing the table of the squares of 2, 3, 4, and 5.
Perfect Squares
2
2
=
3
2
=
4
2
=
5
2
=

Answer 1

Let's complete the table of the squares of 2, 3, 4, and 5:

Perfect Squares:

• \(2^2 = 4\)
• \(3^2 = 9\)
• \(4^2 = 16\)
• \(5^2 = 25\)

Now that we have the perfect squares, we can see that 20 is between the perfect squares of 16 and 25. Therefore, \(4^2\) (16) and \(5^2\) (25) are the two perfect squares that 20 is between.

Thus, we can conclude that:

• \(4 < \sqrt{20} < 5\) or \(4^2 < 20 < 5^2\).