GCF or LCM? EQ: How can I decide whether to use the GCF or LCM to solve real-world problems?

Key Ideas GCF Largest, greatest or maximum number of Grouping Separating Sharing Arranging in rows/groups Cutting LCM Smallest, least or minimum number of Events repeating over and over Events happening again at same time Purchase or get multiple items in order to have enough

GCF or LCM? Ben exercises every 3 days and Isabel every 2 days. Ben and Isabel both exercised today. In how many days will they exercise on the same day? 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 in a row?

Answer: _______________ Viridiana, a costume designer, has 36 bat buttons, 27 pumpkin buttons, and 18 black cat buttons she must use to create costumes. What is the largest number of costumes she can make without having any buttons left over? 1

Zack’s haunted house has an explosion every four minutes. Ross’s haunted house has an explosion every five minutes. How long will it take for the haunted houses to have simultaneous explosions if they both start at the same time? Answer: _______________ 2

Erian is having a party, and she made 63 witch cookies, 45 Frankenstein cookies, and 54 black cat cookies. She wants to make up plates of cookies to set on the tables. If each plate is to contain the same amount of each type of cookie, and there are no left over cookies, what is the greatest number of plates she can make? Answer: _______________ 3

Mariana can make groups of 3, 4, or 9 pumpkins with none left over. What is smallest number of pumpkins she must have to make these groups? Answer: _______________ 4

Hot dogs come in packages of 12 and hot dog buns come in packages of 10. What is the least number of packages of each that Dominique can buy to be able to have a weenie roast with no buns or hot dogs left over? Answer: _______________ 5

Landon has 60 peppermints, 90 candy corns and 120 suckers. He wants to make packages of these candies to bring to his school to pass out to his classmates. What is the maximum number of packages he can make using all items? Answer: _______________ 6

Cecilia has 15 witch temporary tattoos, 30 vampire temporary tattoos, and 48 mummy temporary tattoos. She wants to group her temporary tattoos so that each group has the same number of each tattoo. What is the greatest number of groups she can make? Answer: _______________ 7

Three pieces of timber 42 feet, 49 feet, and 63 feet long have to be divided into planks for a pirate ship of the same length. What is the greatest possible length of each plank? Answer: _______________ 8

You and your three friends go to lunch and find a deal on packages of 6 rats on a stick. You want to buy the minimum number of packages so you each get the same number of rats and none are left over. How many packages must you buy? Answer: _______________ 9

One trip around the cemetery is 440 yards. One frightened sixth grader can complete one lap in 8 minutes, and another can complete it in 6 minutes. What is the least amount of laps it will take for both sixth graders to arrive at their starting point together if they start at the same time and maintain their pace? Answer: _______________ 10