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Thought-Process to Discover Knowledge

Welcome to nubtrek.

Books and other education websites provide "matter-of-fact" knowledge. Instead, nubtrek provides a thought-process to discover knowledge.

In each of the topic, the outline of the thought-process, for that topic, is provided for learners and educators.

Read in the blogs more about the unique learning experience at nubtrek.

In this page, it is explained that a variable is a symbol that represents a number.

click on the content to continue..

How many yellow flowers are shown in the figure?

• 1
• 1
• 2

The answer is '1'

How many petals does the yellow flower have?

• 4
• 8
• 8

The answer is '8'

How many yellow flowers are shown in the figure?

• 1
• 4
• 4

The answer is '4'

How many petals do all the four yellow flowers have?

• 8xx4
• 8xx4
• 8

The answer is '8xx4'

If a person has 2 yellow flowers of the kind shown in the figure, how many petals do those 2 flowers have?

• 8
• 8 xx 2 = 16
• 8 xx 2 = 16

The answer is '8xx2= 16'

A person has x yellow flowers of the kind shown in the figure. The x can be any number.

The number of petals from x flowers is 8x.

•  if x is 2 then the number of petals is 8 xx 2 = 16

•  if x is 6 then the number of petals is 8xx6 = 48

•  etc. In this, the number of flowers is considered as a symbol x and the number of petals is derived as an expression 8x.

The letter x in the expression is called a variable.

How many cherry flowers are shown in the figure?

• 1
• 1
• 2

The answer is '1'

How many petals does the cherry flower have?

• 4
• 5
• 5

The answer is '5'

How many cherry flowers are shown in the figure?

• 1
• 3
• 3

The answer is '3'

How many petals do all the three cherry flowers have?

• 5xx3
• 5xx3
• 5

The answer is '5xx3'

If a person has y cherry flowers of the kind shown in the figure, how many petals do those y flowers have?

• 5
• 5y
• 5y

The answer is '5y'.

If a person has 2 yellow blossom flowers and 3 cherry flowers of the kinds shown in the figure, how many petals do all the flowers have?

• 8+5 = 13
• 8xx2 + 5xx3
• 8xx2 + 5xx3

The answer is '8xx2 + 5xx3'

If a person has x yellow blossom flowers and y cherry flowers of the kinds shown in the figure, how many petals do all the flowers have?

• 8+5 = 13
• 8xx x + 5xx y
• 8xx x + 5xx y

The answer is '8xx x + 5xx y'. x and y are two variables.

In the examples, it is clearly given that

•  an unknown number can be represented using a symbol. eg: x flowers.

•  a symbol, which is used in place of a number, can take a value based on the problem. eg: the number of flowers is taken as x and in a particular basket the number of flowers is 3; then x=3 for that basket.

The symbol is called a variable.

Which of the following is a meaning for the word 'variable'?

• that varies or changes in value
• that varies or changes in value
• that easily gets angry

The answer is 'that varies or changes in value'.

What is the term used to refer to quantities represented with a letter?

• Pronunciation : Say the answer once

a variable is a quantity that can assume different numerical values.

Variable: is a representation of a numerical quantity with a letter or a symbol.
example: number of dogs x and number of cats y.

Solved Exercise Problem:

How many legs will a group of dogs have? Note: The number of dogs in the group is not given, so take the number of dogs as a variable.

• 4
• if the group has x dogs, the number of legs  = 4x
• if the group has x dogs, the number of legs  = 4x

The answer is 'if the group has x dogs, the number of legs  = 4x'

slide-show version coming soon