Writing Basic Algebraic Expressions with Variables

Home | Online Math Tutoring | 6th Grade Math Tutoring | Writing Basic Algebraic Expressions with Variables

What is a variable in an expression?

An algebraic expression has both numbers and variables together with at least one   arithmetic operation.

 

Now when we represent both variable and numbers in an expression this is what it looks like:

x + 4

This means 4 more than x.

How do you write an expression in math?

Let’s say for example, Jim works in a departmental store and gets paid $50 per day and when he lifts boxes from the store room he gets paid tips for that. Now, the number of boxes he lifts depends on the extra time he gets every day.

So, now amount Jim gets paid everyday = {50 + tips}.

 

 

 

On Monday Jim gets $30 as tips and $50 as the sales guy so he earns … $80 in all.

On Tuesday he gets $15 as tips and $50 as the sales guy so he earns …… $65 in all.

So, tips is the variable.

So, instead of writing tips in every case we use an alphabet which in math we call as a variable.

($50 + b) is the amount he earns every day.

What is an example of algebraic expression?

    Check Point

    Write the following in algebraic form.

    1. 89 fewer than a
    2. 45 more than r
    3. 22 times b
    4. What is the sum of 84 and w?
    5. What is y increased by 25?
    1. Karen has h Helen has 2 more pens than Karen. Write an expression for how many pens Helen has.
    1. Max has 12 songs. His friend took m Write an expression that shows how many songs Max has now.
    1. Jen earned 80 points in the Science project. Bruno earned b fewer points than Jen. Write an expression that shows how many extra points Bruno earned. 
    1. Steffi made 62 chocolate chip cookies and w walnut cookies. How many did she make in all?
    Answer key
    1. a – 89
    2. 45 + r
    3. 22b
    4. 84 + w
    5. y + 25
    6. h + 2
    7. 12 – m
    8. 80 – b
    9. (62 + w) cookies