Grade 7

Grade 7Number SystemRoots


Square Roots


In math, the square root is an essential concept and is often introduced in middle school, around grade 7. Let's look at this concept in detail. We will look at what a square root is, how to calculate a square root, and various examples to help clarify the topic.

Understanding square roots

The square root of a number is the value that, when multiplied by itself, gives the original number. In other words, if x is the square root of y, then x * x = y.

The symbol for square root is . So the square root of a number y is usually written as √y.

Illustrating square roots

To better understand square roots, it is helpful to visualize them. Consider a square figure. The area of a square is found by multiplying the length of its side by itself. When we know the area, the square root gives us the length of the side.

Example of square and square root

Let's say we have a square with an area of 25 square units.
√25 = 5

Here, the length of the side of the square is 5 units.

5 5

Calculating the square root

Finding the square root of a perfect square can be simple. A perfect square is a number that is the square of an integer. For example, 1, 4, 9, 16, 25, 36, 49, 64, 81, and 100 are perfect squares.

To find the square root of a perfect square, you can determine which number when multiplied by itself gives a perfect square.

Examples of perfect square

Some perfect square calculations:

  • √1 = 1 (since 1 * 1 = 1)
  • √4 = 2 (since 2 * 2 = 4)
  • √9 = 3 (since 3 * 3 = 9)
  • √16 = 4 (since 4 * 4 = 16)
  • √25 = 5 (since 5 * 5 = 25)

Square roots of non-perfect squares

Not all numbers are perfect squares. When you have a non-perfect square, estimating or using a calculator can help you find the square root. The result will often be an irrational number, which means it can't be expressed exactly as a simple fraction.

Example of a non-perfect class

Find the square root of 20:

√20 ≈ 4.47...

The decimal continues without repeating. This is an estimate.

Assessment techniques

One way to estimate the value of a square root is to find the two nearest perfect squares. For example, when finding √20, we know:

  • √16 = 4 and √25 = 5

Because 20 is between 16 and 25, the square root of 20 is between 4 and 5. You can refine your estimate by checking the squares of numbers between 4 and 5, such as checking whether 4.5 is too high or too low. This is a trial and error approach.

Using a calculator

Many calculators have a square root function that can be accessed by button. Using a calculator you can find square roots quickly and accurately, especially for non-perfect squares.

More examples and exercises

Let's work on some more examples to further strengthen your understanding of square roots.

Example 1: Perfect square root

Find the square root of 64.

Since 8 * 8 = 64, √64 = 8.

8 8

Example 2: Non-perfect square

Find the square root of 50.

Conjecture: Since √49 = 7 and √64 = 8, √50 is slightly greater than 7.

√50 ≈ 7.07

Using a calculator will give a more accurate result.

Conclusion

Square roots are foundational in mathematics, leading to further study in algebra and geometry. It is important to understand both perfect and imperfect squares as you advance in mathematics. Practice finding and estimating square roots using both manual calculations and a calculator to solidify your learning.


Grade 7 → 1.5.1


U
username
0%
completed in Grade 7


Comments