Cube of 991

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 multiplying a negative number by itself three times results in a negative number.

The cube of 991 can be written as 991³, which is the exponential form. Or it can also be written in arithmetic form as 991 × 991 × 991.

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

1. By Multiplication Method 
2. Using a Formula 
3. Using a Calculator

The multiplication method is a process in mathematics used to find the product of 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. 991³ = 991 × 991 × 991

Step 2: You get 973,764,271 as the answer. Hence, the cube of 991 is 973,764,271.

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 991 into two parts, as 900 and 91. Let a = 900 and b = 91, so a + b = 991

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

Step 3: Calculate each term a³= 900³ 3a²b = 3 × 900² × 91 3ab² = 3 × 900 × 91² b³ = 91³

Step 4: Add all the terms together:

(a + b)³ = a³ + 3a²b + 3ab² + b³

(900 + 91)³ = 900³ + 3 × 900² × 91 + 3 × 900 × 91² + 91³

991³ = 729,000,000 + 220,410,000 + 22,292,700 + 753,571

991³ = 973,764,271

Step 5: Hence, the cube of 991 is 973,764,271.

To find the cube of 991 using a calculator, input the number 991 and use the cube function (if available) or multiply 991 × 991 × 991. This operation calculates the value of 991³, resulting in 973,764,271. It’s a quick way to determine the cube without manual computation.

Step 1: Ensure the calculator is functioning properly.

Step 2: Press 9 followed by 9 and 1

Step 3: If the calculator has a cube function, press it to calculate 991³.

Step 4: If there is no cube function on the calculator, simply multiply 991 three times manually.

Step 5: The calculator will display 973,764,271.

• 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: An algebraic expression used to expand the powers of a number, written as (a + b)ⁿ, where ‘n’ is a positive integer. 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: 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.

• Perfect Cube: A number that can be expressed as the cube of an integer, such as 1, 8, 27, etc.

• Volume of a Cube: The amount of space inside a cube, calculated as the cube of the side length.