1-1 Expressions and Formulas
Targets/Goals
● Can I consistently & independently apply &
perform the ORDER of OPERATIONS?
● Can I evaluate ALGEBRAIC EXPRESSIONS?
● Can I manipulate & use FORMULAS when
necessary.
Order of Operations
● What is the Order of Operations?
● Use the phrase . . .
“Please Excuse My Dear Aunt Sally” to
help remember the order in which to
evaluate the expression.
● PEMDAS
PEMDAS
● The P stands for parentheses and
represents all
grouping symbols.
● ( ), [ ], { }
● Simplify within the grouping symbols first.
● If there is more than one grouping
symbol, simplify within the innermost
symbol first.
PEMDAS
● The E stands for exponents.
● Evaluate all powers.
PEMDAS
● M & D stand for multiplication and
division.
● You must simplify whichever comes first
in the expression from left to right.
PEMDAS
● A & S stand for Addition and Subtraction
● You must simplify whichever comes first
in the expression from left to right.
1. Example: Simplify
4  2 
2

83 4
● P First, work inside the brackets.
Evaluate inside the parentheses first: 4 + 2 = 6.
Then raise 6 to the second power: 36.
Now perform addition and subtraction from left
to right: 36 - 8 = 28, now 28 +3 = 31.
Brackets are done.
● M Multiply 31 by 4.
● Final answer is 124.
Algebraic Expressions
● An algebraic expression is an expression
that contains at least one variable.
● You can evaluate an algebraic expression
by replacing each variable with a value
and then applying the Order of Operations.
2.Example: Evaluate a(5a + 2b) if a=3 and
b=-2
● Substitute the values into the expression.
● 3[5(3) + 2(-2)]
● Now apply the Order of Operations:
Inside the brackets, perform multiplication and
division before addition and subtraction
● 5(3) = 15 and 2(-2)= -4
● 3[15 + -4] then 15 + -4 = 11
● 3[11] = 33
Formulas
● Formula is a mathematical sentence that
expresses the relationship between certain
quantities.
● If you know a value for every variable in the
formula except one, you can find the value of
the remaining variable.
● Examples of common formulas:
A = lw
V= lwh
3.Example: Find the area of a rectangle if
the length is 5 cm and the width is 9 cm.
● Apply the formula A = lw
● Substitute the values of the variables
● A = (5 cm)(9 cm)
● A = 45 cm squared
Extra Problems
● 4. GUESS AND CHECK Amanda
received a worksheet from her teacher.
Unfortunately, one of the operations in
an equation was covered by a blot.
What operation is hidden by the blot?
● 10 + 3(4 @ 6) = 4
Extra Problems
● 5. TEMPERATURE The formula F = C +
32 gives the temperature in degrees
Fahrenheit for a given temperature 5 in
degrees Celsius. What is the temperature in
degrees Fahrenheit when the temperature is
–40 degrees Celsius?
Homework
● 1st and 4th
● p.7 #’s 14-16,22-24,26,30,34,40
● 2nd and 3rd
● p.7 #’s 16,22,24,26,34,40,44