Examples of variables are:
The number of people in a bus.
The number of millemetres of rain in a day.
The number of correct answers in a test.
How do we show a variable?
We usually represent a variable by a letter.
We can use any letter
but x is the letter used very often.
Examples:
Let x be the number of people in a bus.
Let y be the number of millemetres of rain in a day.
Let z be the number of correct answers in a test.
Notice that we must be able to
count or measure a variable.
Examples:
We can count
the number of people in a bus.
We can measure
the number of millemetres of rain in a day.
We can count
the number of correct answers in a test.
TRUE OR FALSE
The number of apples in a box is a variable.
The height of a tree in metres is a variable.
QUESTIONS AND ANSWERS
Is the number of radios in a radio shop a variable?
Yes.
It makes sense to say:
Let x be the number of radios in a radio shop.
Is your age a variable?
Yes.
It makes sense to say:
Let x be the number of years of your age.
INTRODUCTION TO ALGEBRA - FROM NUMBERS TO VARIABLES
This video states that
if you are new to algebra, then this is a good place to start
If there exists a number
but you do not know the value of the number
then this unknown number can be represented by the letter x
and then the letter x represents a variable (the unknown number)
But a variable could also be represented by another letter eg y or z
Created And Edited by Dr David Cornelius an Independent Private Maths Tutor with over 25 years of experience and The Secretary of The Association of Tutors in the UK for 15 years.
