# WarmUp Find the GCF and LCM of each

• Slides: 18

Warm-Up Find the GCF and LCM of each set of numbers: 15 8 35 18 60 28

What am I Learning Today? GCF and LCM How will I show that I learned it? Determine the GCF or LCM between sets of data when data is presented as word problems. Use keywords to determine if a word problem is a GCF or LCM problem.

GCF or LCM How can you tell if a word problem requires you to use Greatest Common Factor or Least Common Multiple to solve?

Keywords for GCF Greatest Largest Maximum Dividing something Cutting something into pieces

Key words for LCM Smallest Minimum First Least Next Repeated over and over Multiple items When both will meet again When both will be equal in length

1. GCF or LCM? Peter has 18 oranges and 27 pears. He wants to make fruit baskets with the same number of each fruit in each basket. What is the greatest number of fruit baskets he can make? KEYWORD: greatest = GCF

2. GCF or LCM? Dr. Doyle’s band students have been invited to march in a parade along with another school. Since one band marches directly behind another, Dr. Doyle must divide the musicians so all the rows have the same number of students. Dr. Doyle had 36 students and the other band has 60 students. KEYWORD: divide = GCF

3. GCF or LCM? Ms. Neely is making 30 school supply baskets for her students. Notepads come in packs of 5. Erasers come in packs of 15. Markers come in packs of 3. What is the least number of each package should buy to have one of each item in every basket and no supplies left over? KEYWORD: least = LCM

4. GCF or LCM? Dog cookies come in packages of 6, and bones in bags of 9. If there are 18 dogs, what is the least number of packages and bags needed so that each dog has a treat box with one bone and one cookie and there are no bones or cookies left over? You could: Draw cookies in groups of 6. Draw bones in groups of 9. Stop when you have drawn the same number of each. Is there are easier way? KEYWORD: least = LCM

5. GCF or LCM? I am planting 50 apple trees and 30 peach trees. I want the same number and type of trees per row. What is the maximum number of trees I can plant per row? KEYWORD: maximum = GCF

6. GCF or LCM? Sean has 8 -inch pieces of toy train track and Ruth has 18 -inch pieces of train track. How many of each piece would each child need to build tracks that are equal in length? KEYWORDS: Equal in length = LCM

7. GCF or LCM? Rosa is making a game board that is 16 inches by 24 inches. She wants to use square tiles. What is the largest tile she can use? KEYWORD: largest = GCF

8. GCF or LCM? Ben exercises every 12 days and Isabel every 8 days. Ben and Isabel both exercised today. How many days will it be until they exercise together again? KEYWORD: together again = LCM

9. GCF or LCM? Q 100 gave away a \$100 bill for every 100 th caller. Every 30 th caller received free concert tickets. How many callers must get through before one of them receives both the money and concert tickets? KEYWORD: both = LCM

10. GCF or LCM? Mrs. Evans has 120 crayons and 30 pieces of paper to give to her students. What is the largest number of students she can have in her class so that each student gets an equal number of crayons and an equal number of paper? KEYWORD: largest = GCF

11. GCF or LCM? Two bikers are riding a circular path. The first rider completes a round in 12 minutes. The second rider completes a round in 18 minutes. If they both started at the same place and time and go in the same direction, after how many minutes will they meet again at the starting point? KEYWORDS: meet again = LCM

12. GCF or LCM? The Student Forum has decided to raise money for new PE equipment. They decide to sell breakfast sandwiches. Bagels come in packs of 8, eggs in cartons of 12, and they need to sell 48 sandwiches to reach their goal. What is the least number of packs and cartons so that they can sell exactly sandwiches? KEYWORD: least = LCM 48

13. GCF or LCM? Samantha has two pieces of cloth. One piece is 72 inches wide and the other piece is 90 inches wide. She wants to cut both pieces into strips of equal width that are as wide as possible. How wide should she cut the strips? KEYWORD: cut = GCF