Last updated on May 27th, 2025
When a number is multiplied by itself thrice, the resultant number is called the cube of a number. Cubing is used while comparing sizes of objects or things with cubic measurements. In this topic, we shall learn about the cube of 821.
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 821 can be written as 821³, which is the exponential form. Or it can also be written in arithmetic form as, 821 × 821 × 821.
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. 821³ = 821 × 821 × 821 Step 2: You get 553,033,061 as the answer. Hence, the cube of 821 is 553,033,061.
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 821 into two parts, as 800 and 21. Let a = 800 and b = 21, so a + b = 821 Step 2: Now, apply the formula (a + b)³ = a³ + 3a²b + 3ab² + b³ Step 3: Calculate each term a³ = 800³ 3a²b = 3 × 800² × 21 3ab² = 3 × 800 × 21² b³ = 21³ Step 4: Add all the terms together: (a + b)³ = a³ + 3a²b + 3ab² + b³ (800 + 21)³ = 800³ + 3 × 800² × 21 + 3 × 800 × 21² + 21³ 821³ = 512,000,000 + 403,200 + 352,800 + 9,261 821³ = 553,033,061 Step 5: Hence, the cube of 821 is 553,033,061.
To find the cube of 821 using a calculator, input the number 821 and use the cube function (if available) or multiply 821 × 821 × 821. This operation calculates the value of 821³, resulting in 553,033,061. It’s a quick way to determine the cube without manual computation. Step 1: Ensure the calculator is functioning properly. Step 2: Press 8 followed by 2 and 1 Step 3: If the calculator has a cube function, press it to calculate 821³. Step 4: If there is no cube function on the calculator, simply multiply 821 three times manually. Step 5: The calculator will display 553,033,061.
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.
There are some typical errors that kids might make during the process of cubing a number. Let us take a look at five of the major mistakes that kids might make:
What is the cube and cube root of 821?
The cube of 821 is 553,033,061 and the cube root of 821 is approximately 9.345.
First, let’s find the cube of 821. We know that cube of a number, such that x³ = y Where x is the given number, and y is the cubed value of that number So, we get 821³ = 553,033,061 Next, we must find the cube root of 821 We know that cube root of a number ‘x’, such that ∛x = y Where ‘x’ is the given number, and y is the cube root value of the number So, we get ∛821 ≈ 9.345 Hence, the cube of 821 is 553,033,061 and the cube root of 821 is approximately 9.345.
If the side length of the cube is 821 cm, what is the volume?
The volume is 553,033,061 cm³.
Use the volume formula for a cube V = Side³. Substitute 821 for the side length: V = 821³ = 553,033,061 cm³.
How much larger is 821³ than 401³?
821³ – 401³ = 548,584,560.
First, find the cube of 821³, that is 553,033,061 Next, find the cube of 401³, which is 4,448,501 Now, find the difference between them using the subtraction method. 553,033,061 – 4,448,501 = 548,584,560 Therefore, 821³ is 548,584,560 larger than 401³.
If a cube with a side length of 821 cm is compared to a cube with a side length of 10 cm, how much larger is the volume of the larger cube?
The volume of the cube with a side length of 821 cm is 553,033,061 cm³.
To find its volume, we multiply the side length by itself three times (since it’s a 3-dimensional object). Cubing 821 means multiplying 821 by itself three times: 821 × 821 = 674,041, and then 674,041 × 821 = 553,033,061. The unit of volume is cubic centimeters (cm³), because we are calculating the space inside the cube. Therefore, the volume of the cube is 553,033,061 cm³.
Estimate the cube of 820.9 using the cube of 821.
The cube of 820.9 is approximately 553,033,061.
First, identify the cube of 821, The cube of 821 is 821³ = 553,033,061. Since 820.9 is only a tiny bit less than 821, the cube of 820.9 will be almost the same as the cube of 821. The cube of 820.9 is approximately 553,033,061 because the difference between 820.9 and 821 is very small. So, we can approximate the value as 553,033,061.
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 equals 8. Perfect Cube: A number that can be expressed as the cube of an integer. For example, 27 is a perfect cube because it is 3³. Cube Root: The number that, when multiplied by itself twice, gives the original number. For example, the cube root of 8 is 2, because 2 × 2 × 2 = 8.
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.
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