1-1 Variables and Expressions
variable- a letter that stands for a number
*In Algebra we will write products involving variables without
the multiplication symbol
Ex. 5t means 5 t
12y means 12 y
* Be sure to always write the variable second
Numerical Expression Two or more numbers combined with operations signs (there is no
equals sign)
Ex. 4 + 6 8 - 4 14
2
Variable ExpressionAn expression with one or more variables
Ex. 3y m + 5 -16
r
Drag each expression to the correct box
Numerical
Variable
w
9
5y
y+2
56 - x
3m + 7
12
2
32- 5
3
2
4+8
Write a variable expression for each word phrase.
1.) Nine more than a number y
2.) 4 less than a number n
3.) A number z times 3
4.) 8 more than 5 times a number t
5.) A number q divided by 7
Write an expression for each
1.) Vicki and Tamra are working on their math homework together. Vicki has worked p
problems and Tamra has worked 4 times as many as Vicki. Write an expression to show how
many problems they have worked altogether.
2.) Frank had 3b baseball cards and his brother had b baseball cards. They combined their
cards, and then gave away 2b cards. Write an expression to shows how many they have left.
1-3 Variables and Expressions
To evaluate a variable expression, replace each variable with the given number.
Use proper the proper order of operations.
Evaluate when x = -5 and y = 6
1.) 3x 2.) xy
3.) 12 + x + y 4.) 4y +9
Evaluate when x = 5 and y = 6
5.) 12 6.) 6(x+y)
y
7.) 3y2 + 2x 8.) 2x+3y
7