Name:______Class:______Date______

SWBAT: Identify and solve GCF real world problems by referring to the GCF checklist and using prime factorization

Do Now
GCF Using Prime Factorization
1.)Find the GCF of 30 and 20 using a Factor Tree to help you find the prime factorization of each number.
a.)Factor Trees
30 20
b.)Write the prime factorization of 30 in expanded form
30 = ______
20 = Write the prime factorization of 20 in expanded form.
c.)What factors are a match in both lists?
d.)What is the GCF of 20 and 30? ______
2.)Which set of numbers are relatively prime?
a.)5 and 10 b.) 8 and 21
Class Notes
How do I know if using the GCF can help me solve a problem?
GCF Problem Solving Checklist
Checklist
  • Do I want to split things into smaller (but equal) sections?
  • Are we trying to figure how many people to invite?
  • Are we trying to arrange or divide something into (equal or even) rows or groups?
/ Key Words:
I Do- Teacher Example
Jamie baked 12 oatmeal cookies and 16 chocolate chip cookies to package in plastic containers for her friends at school. She wants to divide the cookies into identical containers so that each container has the same number of each kind of cookie. If she wants each container to have the greatest number of cookies possible, how many containers does she need?
1.)Use the checklist to figure out WHAT we are trying to do in this problem.
In this problem Jamie wants to ______
______.
2.)What Keywords are used in this problem?
______and ______
3.)Solve using a factor tree to help you find the prime factorization of each number
Answer: Jamie needs ______containers
We Do - Scholar Example
REFER TO CHECKLIST ON PAGE 2 TO HELP YOU ANSWER THIS QUESTION.
Mrs. Jones has 18 boys and 27 girls in choir. She wants them to stand in equal rows. Only boys or girls will be in each row. What is the greatest number of students that can stand in each row?
1.)Use the checklist to figure out WHAT we are trying to do in this problem.
In this problem Mrs. Jones wants to ______
______.
2.)What Keywords are used in this problem?
3.)Solve using a factor tree to help you find the prime factorization of each number
Answer: Use a complete sentence to answer:
The greatest number______
______
You Do - I help
There are 6 cellos, 12 violins, and 21 violins playing in an orchestra concert. Mr. Johnson wants them arranged in rows, and he wants each section to have the same number of rows. What is the greatest number of rows the orchestra would have?
1.)Use the checklist to figure out WHAT we are trying to do in this problem.
In this problem ______
______
2.)What Keywords are used in this problem?
Bachelors Practice
A. )Quixing has 36 glittery stickers and 12 heart stickers. She wants to divide the stickers evenly among her friends. Find the greatest number of friends that Quixing can give stickers to if each friends gets the same number of each type of sticker.
1.)Use the checklist to figure out WHAT we are trying to do in this problem.
In this problem ______
______.
2.)What Keywords are used in this problem?
3.)Solve using a factor tree to help you find the prime factorization of each number
Answer (In a complete sentence):
B.) Ms. Vinceslio has 35 inches of purple ribbon and 28 inches of green ribbon. She needs to cut the ribbon into even pieces for an art project and doesn’t want to have any left over. What is the greatest length of ribbon pieces that she could use?
1.)Use the checklist to figure out WHAT we are trying to do in this problem.
In this problem ______
______.
2.)What Keywords are used in this problem?
3.)Solve using a factor tree to help you find the prime factorization of each number
Answer (in a complete sentence)
Masters Practice (Challenge Problems)
C.) The cafeteria is making identical fruit baskets. They have 42 apples, 36 bananas, and 18 oranges. They want each basket to have the same numbers of each type of fruit. What is the greatest number of baskets they can make?
1.)Use the checklist to figure out WHAT we are trying to do in this problem.
______
______.
2.)What Keywords are used in this problem?
3.)Solve using a factor tree to help you find the prime factorization of each number
Answer (in a complete sentence)
Exit Ticket

Mastered Almost  Not Yet

The cast of a play had a party at the drama teacher’s house. There were 20 cookies and 40 carrot sticks served as refreshments. Each cast member had the same number of whole cookies and the same number of whole carrot sticks. Nothing was left over. The drama teacher did not eat. What is the greatest number of members might have been at the party?

1.)Use the checklist to figure out WHAT we are trying to do in this problem.

We are trying to figure out how many cast members might have been at the party

by______

______

2.)What Keywords are used in this problem?

______and ______

3.)Solve using a factor tree to help you find the prime factorization of each number

Answer: There were ______cast members at the party.

Homework
Must show all work and answer all problems to get full credit

Noah and his friends are going on a hiking trip. Noah wants to make snack packs of apples and trail mix to take on the trip. He has 24 apples and 36 small bags of trail mix. What is the greatest number of snack packs Noah can make if each pack must have exactly the same number of apples and exactly the same number of trail mix?

1.)Use the checklist to figure out WHAT we are trying to do in this problem.

In this problem ______

______.

2.)What Keywords are used in this problem?

3.)Solve using a factor tree to help you find the prime factorization of each number

Answer (in a complete sentence)