Writing Expressions
Fern has 7 red pens and b blue pens. How many pens does Fern have?
7 + b
Roger bought some used CDs at a garage sale. He gave 9 CDs to his dad and kept 12 of them for himself. How many CDs did Roger buy at the garage sale?
"c - 9 = 12" or "c - 12 = 9" or "9 + 12 = c" or 12 + 9 = c"
18 + x = 34
x = 16
25y if y = 0
0
An unknown part of an equation, represented by a letter.
variable
Sarah had 15 quarters. She used q quarters in the vending machine. How many quarters does Sarah have left?
15 - q
Felicia and Sam sold 103 muffins at the bake sale. Felicia sold 25 muffins. How many muffins did Sam sell at the bake sale?
"45 + s = 103" or "s + 45 = 103" or "103 - 45 = s" or 103 - s = 45"
x - 45 = 88
x = 43
145t + 3
if t = -6
-867
Each group of variables and numbers, separated by addition or subtraction signs.
term
Macy had d dollars. She gave half of her dollars to charity. How many dollars did she give to charity.
1/2 d
Francine walked 44 miles last month on her days off. She walked 4 miles each time. How many days did Francine have off?
"4d = 44" or "44/4 = d" or 44/d = 4"
x/3 = 10
x = 30
12f if f = 13
156
Variables, numbers, and operations with an equal sign.
equation
A candy company divided c bags of candy into 12 boxes. How many bags of candy are in each box?
c/12
Alison took 51 candy bars and split them into groups to give out for Halloween. She put 3 bars in each group. How many bunches did Alison make?
"51/3 = b" or "51/b = 3" or "3b = 51"
15 * x = 75
x = 5
7(1/2 + r)
if r = 3/4
8.75
A combination of numbers, variables, and symbols that illustrate a mathematical relationship but has no equal sign
expression
Five times the sum of 4 and t
5(4 + t)
The sum of 13 and the quotient of 6 and x is equal to 15.
"13 + 6/x = 15"?
x - 4 = 3
x = 7
82 - 3t if t = 14
The answer to a subtraction problem
difference