Transcript Lesson 1-4 Order of Operations

1. If an ape at the zoo drank 2.38 gallons of
water out of a full five-gallon drum, how
much water would be left in the drum?
2. McKayla bought a picture frame that cost
$6.95, a candle that cost $3.25, and a bottle
of lotion that cost $5.85. Estimate the total
for the items purchased?
• Find the greatest common factor of two or more
numbers.
• Common factor – factors that are shared by two or
more numbers
• Greatest Common Factor (GCF) – the largest
number that two or more numbers share as a
factor
Identify Common Factors
Identify the common factors of 20 and 36.
First, list the factors by pairs for each number.
Circle the
common
factors.
Answer: The common factors are 1, 2, and 4.
Identify the common factors of 24 and 42.
A.
B.
C.
D.
A
B
C
D
Find the GCF by Listing Factors
Find the GCF of 36 and 48.
First, make an organized list of the factors for each
number.
36: 1 × 36, 2 × 18, 3 × 12, 4 × 9, 6 × 6 → 1, 2, 3, 4, 6, 9,
12, 18, 36
48: 1 × 48, 2 × 24, 3 × 16, 4 × 12, 6 × 8 → 1, 2, 3, 4, 6, 8,
12, 16, 24, 48
The common factors are 1, 2, 3, 4, 6, and 12, and the
greatest of these is 12. So, the greatest common factor
or GCF of 36 and 48 is 12.
Find the GCF of 45 and 75.
1.
2.
3.
4.
A
B
C
D
Find the GCF by Using Prime Factors
Divide by prime numbers.
Divide both 52 and 78 by 2. Then
divide the quotients by 13.
Answer: So, the GCF of 52 and 78 is 2 × 13 or
26.
Find the GCF of 64 and
A.
B.
80.C.
D.
A
B
C
D
Use the GCF to Solve a Problem
SALES Anna sells bags of different kinds of
cookies. She made $27 selling bags of
peanut butter cookies, $18 from chocolate
chip cookies, and $45 selling bags of
oatmeal cookies. Each bag of cookies costs
the same amount. What is the most that
Anna could charge for each bag of cookies?
factors of 18:
1, 2, 3, 6, 9, 18
factors of 27:
1, 3, 9, 27
factors of 45:
1, 3, 5, 9, 15, 45
List all the factors of
each number. Then
find the greatest
common factor.
The GCF of 18, 27, and 45 is 9.
Answer: So, the most she could charge for each bag
is $9.
Mr. Morgan has 24 Snickers bars and 36
chocolate chip cookies to use as prizes for
the spelling bee. If he wants every winner to
receive the same number of Snickers bars as
cookies, what is the greatest number of
winners he could have if he gives away all the
prizes?
A.
B.
C.
D.
A
B
C
D
A bag of gum has 3 different flavors: 8
peppermint, 12 cinnamon, and 16 bubblegum.
What is the greatest number of people who
could share the whole bag of gum if each
person received an equal amount of each
flavor?
A.
B.
C.
D.
A
B
C
D