WRITING EXPRESSIONS
AND EQUATIONS
Math 1
KEY WORDS FOR OPERATIONS
• ADDITION
–
–
–
–
–
–
Add
More than
Increased by
All together
Plus
sum
• SUBTRACTION
–
–
–
–
–
–
Difference
Left over
Left
Decreased by
Minus
Less then
• MULTIPLICATION
–
–
–
–
–
–
Product
Times
All together
Multiplied by
By
of
• DIVISION
–
–
–
–
Quotient
Into
Groups
divide
WRITING AN EXPRESSION
• Using key words, translate the verbal expression
into mathematical expression
• Problem:
– A number increased by 5
• Verbal Model
A number
+
5
• Substitute
– Put into mathematical terms
• N+5
• Solve
– Can we evaluate this expression?
• No, because we don’t know what n equals
WRITE A VARIABLE EXPRESSION
N-7
• 7 less than a number
• 3 more than twice a number
3 + 2n
• 4 decreased by the quotient of a number
4 – n/7
and 7
• 42 divided by a number
42 ÷ n
• ½ of a number decreased by 12 1
2
n  12
WRITING AN EQUATION
• Using key words, translate the sentence into an equation
• Problem:
– The Times Square New Year’s Eve Ball drops a total of 77
feet in 60 seconds. After 54 seconds the ball has dropped 69
feet. How many more feet will the ball drop?
• Verbal Model
Total distance ball
drops
=
Distance ball has
dropped
• Substitute
– Put into mathematical terms
• 77
=
69
+
d
• Solve
– 69 plus what number equals 77
– D = 8 feet
+
Distance left to drop
WRITE AN EQUATION
• 16 increased by a number is 27.
16 + n = 27
• The difference of twice a number and 3 equals 4.
2n – 3 = 4
• The product of 4 and a number is 36.
4n = 36
• -3 is equal to twice the sum of a number and 2.
-3 = 2(n + 2)
Writing Expressions and Equations
1. Identify your parts (use key words)
2. Give a variable to your unknown
3. Mark your parts with mathematical
symbols
4. Write in mathematical terms.