B2.7 Represent and solve problems involving multiplication and division, including problems that involve groups of one half, one fourth, and one third, using tools and drawings.
Activity 1: Caesar's Birthday
The Rodriguez family is having guests over for dinner to celebrate their son Cesar's birthday. Veronica, the oldest daughter of the family, wants to set the tables for the event. Including her family members, 3 families of 6 people and 4 families of 4 people will be present. How many tables of 4 people will be needed? How many forks, spoons and knives? How many 8-serving cakes will she need to buy?
Ask students the following questions:
- What do you think is the first step in solving this problem? the second ? the third? Why?
- Which equations represent the situation? Which elements are known? Which elements are unknown? How do you know?
- Which model could be used to solve this problem? Justify your choice.
- What manipulatives could be used to represent the situation? Explain your choice.
- Can we check the reasonableness of our answers using repeated addition or subtraction? Justify your answer.
Activity 2: Preparation of Fruit Skewers
Mrs. Budak must prepare 6 fruit skewers. Each skewer must contain \(3 \frac{1}{2} \) strawberries, \( \frac{1}{4} \) orange, \(4 \frac{1}{2} \) grapes and \( \frac{1}{3} \) of a banana. How many strawberries, oranges, grapes and bananas does she need to prepare the fruit skewers?
Ask students questions such as:
- What are the equations that represent the situation? Which elements are known? Which elements are unknown? How do you know?
- What model or diagram could be used to represent the situation? Explain your choice.
- What strategies can we use to solve the problem? Explain your choice.
- Can we check the reasonableness of our answer using repeated addition or subtraction? Justify your answer.
Activity 3: Cleaning the Aquarium
Micah needs to clean his aquarium. To do this, he must add \(4 \frac{1}{2} \) millilitres of cleaning product to 8 litres of water. Knowing that his aquarium contains only 4 litres of water, how many millilitres of cleaning product should he mix in the water of his aquarium?
Ask students questions such as:
- Which equation represents the situation? Which elements are known? Which elements are unknown? How do you know?
- Which model could be used to solve this problem? Justify your choice.
- What manipulatives could be used to represent the situation? Explain your choice.
- How could we check the reasonableness of our answer? Justify your answer.