Cube Roots
Chapter Name : Cubes And Cube Roots |
Sub Topic Code : 104_08_07_03_02 |
Topic Name : Cube Roots |
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Sub Topic Name : Cube Root Of A Cube Number |
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Introduction
What is a cube root?
Pre-Requisites:
Basic knowledge about arithmetic operations, numbers, cubes
Activity:
The cube of a number is found by multiplying the number with itself twice. Number is split in digits of three from the right to find the digit of the cube root in its respective place. Each group represents a place with the right most in units place and so on.
Real Life Question:
What is the capacity of your overhead tank?
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Cube root | If a number can be written as the product of same number three times, then the number in the product is called cube root of the number |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Abacus | Split the number into groups of three from the right. The first three digits give the units place. The next tens and so on. Now represent the first group. Check the units place and see which cube of digit equals that digit. Now represent the second group and see the adjacent lower perfect cube and higher perfect cube. Find the cube root of the lower perfect cube. |
Real life uses :
Volume estimation, height estimation in a cuboid, toys, electrical resistance, induction instruments
Practical examples around us
| Examples | Explainations |
|---|---|
| Overhead tanks | The volume of a tank is a cubic unit. For a cube tank, the volume will be the cube of the side. |
| Rubber band toys | The rubber band planes whose propeller is twisted first and rotates when left uses the cubic equations. |
What you learn in Theory:
The cube of a number is the product of the number with its square. The cube roots of a cube can be found by splitting the cube number into groups of three.
What you learn in Practice:
Find the respective places of the groups. If the number in the group isn’t a perfect cube then find the adjacent low perfect cube. Divide cube number with the prime numbers until the quotient becomes 1. If quotient is 1 and the prime numbers are used in the multiples of 3, then the number is a perfect cube. The product of prime numbers in multiples of 3 is the cube root.