Square of 8.4
2026-02-28 13:42 Diff
https://brightchamps.com/en-us/math/algebra/square-of-8.4

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Last updated on August 5, 2025

The product of multiplying a number by itself is the square of a number. Square is used in programming, calculating areas, and so on. In this topic, we will discuss the square of 8.4.

What is the Square of 8.4

The square of a number is the product of the number by itself. The square of 8.4 is 8.4 × 8.4. The square of a number can end in any digit since it involves decimal numbers. We write it in math as 8.4², where 8.4 is the base and 2 is the exponent. The square of a positive and a negative number is always positive.

For example, 5² = 25; (-5)² = 25.

The square of 8.4 is 8.4 × 8.4 = 70.56.

Square of 8.4 in exponential form: 8.4²

Square of 8.4 in arithmetic form: 8.4 × 8.4

How to Calculate the Value of the Square of 8.4

The square of a number is multiplying the number by itself. So let’s learn how to find the square of a number. These are the common methods used to find the square of a number.

  • By Multiplication Method
  • Using a Formula
  • Using a Calculator

By the Multiplication Method

In this method, we will multiply the number by itself to find the square. The product here is the square of the number. Let’s find the square of 8.4.

Step 1: Identify the number. Here, the number is 8.4.

Step 2: Multiplying the number by itself, we get, 8.4 × 8.4 = 70.56.

The square of 8.4 is 70.56.

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Using a Formula (a²)

In this method, the formula, a² is used to find the square of the number, where a is the number.

Step 1: Understanding the equation

Square of a number = a² a² = a × a

Step 2: Identifying the number and substituting the value in the equation.

Here, 'a' is 8.4.

So: 8.4² = 8.4 × 8.4 = 70.56

By Using a Calculator

Using a calculator to find the square of a number is the easiest method. Let’s learn how to use a calculator to find the square of 8.4.

Step 1: Enter the number in the calculator Enter 8.4 in the calculator.

Step 2: Multiply the number by itself using the multiplication button (×) That is 8.4 × 8.4

Step 3: Press the equal to button to find the answer Here, the square of 8.4 is 70.56.

Tips and Tricks for the Square of 8.4

Tips and tricks make it easy for students to understand and learn the square of a number. To master the square of a number, these tips and tricks will help students.

  • The square of an even number is always an even number. For example, 6² = 36
  • The square of an odd number is always an odd number. For example, 5² = 25
  • The square of a decimal may not follow the same last-digit rules as whole numbers.
  • If the square root of a number is a fraction or a decimal, then the number is not a perfect square. For example, √1.44 = 1.2
  • The square root of a perfect square is always a whole number. For example, √144 = 12.

Common Mistakes to Avoid When Calculating the Square of 8.4

Mistakes are common among kids when doing math, especially when it comes to finding the square of a number. Let’s learn some common mistakes to master the squaring of a number.

Problem 1

Find the side length of a square, where the area of the square is 70.56 cm².

Okay, lets begin

The area of a square = a²

So, the area of a square = 70.56 cm²

So, the side length = √70.56 = 8.4.

The length of each side = 8.4 cm

Explanation

The side length of a square is 8.4 cm. Because the area is 70.56 cm², the length is √70.56 = 8.4.

Well explained 👍

Problem 2

Anna is planning to cover her square garden wall with tiles, each costing 10 dollars per square meter. If the wall's length is 8.4 meters, how much will it cost to cover the entire wall?

Okay, lets begin

The length of the wall = 8.4 meters

The cost to cover 1 square meter of wall = 10 dollars.

To find the total cost to cover, we find the area of the wall,

Area of the wall = area of the square = a²

Here a = 8.4

Therefore, the area of the wall = 8.4² = 8.4 × 8.4 = 70.56.

The cost to cover the wall = 70.56 × 10 = 705.6.

The total cost = 705.6 dollars

Explanation

To find the cost to cover the wall, we multiply the area of the wall by the cost to cover per square meter. So, the total cost is 705.6 dollars.

Well explained 👍

Problem 3

Find the area of a circle whose radius is 8.4 meters.

Okay, lets begin

The area of the circle = 221.67 m²

Explanation

The area of a circle = πr²

Here, r = 8.4

Therefore, the area of the circle

= π × 8.4²

= 3.14 × 8.4 × 8.4

= 221.67 m².

Well explained 👍

Problem 4

The area of a square is 70.56 cm². Find the perimeter of the square.

Okay, lets begin

The perimeter of the square is 33.6 cm.

Explanation

The area of the square = a²

Here, the area is 70.56 cm²

The length of the side is √70.56 = 8.4

Perimeter of the square = 4a

Here, a = 8.4

Therefore, the perimeter = 4 × 8.4 = 33.6 cm.

Well explained 👍

Problem 5

Find the square of 9.

Okay, lets begin

The square of 9 is 81.

Explanation

The square of 9 is multiplying 9 by 9.

So, the square = 9 × 9 = 81.

Well explained 👍

FAQs on Square of 8.4

1.What is the square of 8.4?

The square of 8.4 is 70.56, as 8.4 × 8.4 = 70.56.

2.What is the square root of 8.4?

The square root of 8.4 is approximately ±2.9.

3.Is 8.4 a whole number?

No, 8.4 is not a whole number; it is a decimal number.

4.What are the first few multiples of 8.4?

The first few multiples of 8.4 are 8.4, 16.8, 25.2, 33.6, 42, 50.4, and so on.

5.What is the square of 8?

Important Glossaries for Square of 8.4.

  • Decimal number: A number that consists of a whole number and a fractional part separated by a decimal point. For example, 8.4, 3.5, etc.
  • Exponential form: Exponential form is the way of writing a number in the form of a power. For example, 8.4² where 8.4 is the base and 2 is the exponent.
  • Square root: The square root is the inverse operation of squaring. The square root of a number is a number whose square is the number itself.
  • Perimeter: The perimeter is the total distance around the edge of a two-dimensional shape.
  • Perfect square: A perfect square is a number that is the square of an integer or a whole number. For example, 64 is a perfect square because it is 8².

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Jaskaran Singh Saluja

About the Author

Jaskaran Singh Saluja is a math wizard with nearly three years of experience as a math teacher. His expertise is in algebra, so he can make algebra classes interesting by turning tricky equations into simple puzzles.

Fun Fact

: He loves to play the quiz with kids through algebra to make kids love it.