Cube of 391

A cube number is a value obtained by raising a number to the power of 3, or by multiplying the number by itself three times.

When you cube a positive number, the result is always positive.

When you cube a negative number, the result is always negative.

This is because a negative number by itself three times results in a negative number.

The cube of 391 can be written as 391³, which is the exponential form.

Or it can also be written in arithmetic form as, 391 × 391 × 391.

In order to check whether a number is a cube number or not, we can use the following three methods: multiplication method, a factor formula (a³), or by using a calculator. These three methods will help kids to cube the numbers faster and easier without feeling confused or stuck while evaluating the answers.

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

The multiplication method is a process in mathematics used to find the product of two numbers or quantities by combining them through repeated addition. It is a fundamental operation that forms the basis for more complex mathematical concepts.

Step 1: Write down the cube of the given number. 391³ = 391 × 391 × 391

Step 2: You get 59,708,671 as the answer. Hence, the cube of 391 is 59,708,671.

The formula (a + b)³ is a binomial formula for finding the cube of a number. The formula is expanded as a³ + 3a²b + 3ab² + b³.

Step 1: Split the number 391 into two parts, as a and b. Let a = 390 and b = 1, so a + b = 391

Step 2: Now, apply the formula (a + b)³ = a³ + 3a²b + 3ab² + b³

Step 3: Calculate each term a³ = 390³ 3a²b = 3 × 390² × 1 3ab² = 3 × 390 × 1² b³ = 1³

Step 4: Add all the terms together: (a + b)³ = a³ + 3a²b + 3ab² + b³ (390 + 1)³ = 390³ + 3 × 390² × 1 + 3 × 390 × 1² + 1³ 391³ = 59,319,000 + 456,300 + 1,170 + 1 391³ = 59,708,671

Step 5: Hence, the cube of 391 is 59,708,671.

To find the cube of 391 using a calculator, input the number 391 and use the cube function (if available) or multiply 391 × 391 × 391. This operation calculates the value of 391³, resulting in 59,708,671. It’s a quick way to determine the cube without manual computation.

Step 1: Ensure the calculator is functioning properly.

Step 2: Press 3 followed by 9 and 1

Step 3: If the calculator has a cube function, press it to calculate 391³.

Step 4: If there is no cube function on the calculator, simply multiply 391 three times manually.

Step 5: The calculator will display 59,708,671.

• The cube of any even number is always even, while the cube of any odd number is always odd.
   
• The product of two or more perfect cube numbers is always a perfect cube.
   
• A perfect cube can always be expressed as the product of three identical groups of equal prime factors.

• Binomial Formula: It is an algebraic expression used to expand the powers of a number, written as (a + b)ⁿ, where ‘n’ is a positive integer raised to the base. The formula is used to find the square and cube of a number.
   
• Cube of a Number: Multiplying a number by itself three times is called the cube of a number.
   
• Exponential Form: It is a way of expressing numbers using a base and an exponent (or power), where the exponent value indicates how many times the base is multiplied by itself. For example, 2³ represents 2 × 2 × 2, which equals 8.
   
• Volume: The amount of space occupied by a 3-dimensional object, such as a cube, calculated as the cube of its side length.
   
• Perfect Cube: A number that can be expressed as the cube of an integer.