B2.2 Recall and demonstrate multiplication facts for 1 × 1 to 10 × 10 and related division facts.
Activity 1: Sometimes Upside Down?
Directions
Ask students to represent \(5\; \times \;8\) and \(8\; \times \;5\) using arrays.
Here are some examples of possible representations:
Proceed in the same way with various multiplications of 2 numbers.
Intervention
Ask questions to help understand the commutative property of multiplication, such as :
- What do you see?
- How many tokens are there? rows? columns?
- I rotate the array 90° (as if it falls over). How many are there now?
- What is the product of 5 and 8? What other multiplication fact resembles this?
- By rotating the arrays, what other pairs of numbers give the same product?
Source : Guide d'enseignement efficace des mathématiques de la maternelle à la 3e année, p. 41-42.
Activity 2: The Big Race
Strategies : + 1, + 2, + 0, - 0, doubles, numbers close to doubles, grouping by tens
Material
- Appendix FR22 (game The Big Race) (one per student)
- pencils
- tokens
The big race can be used to familiarize students with all the strategies related to multiplication in a paper-and-pencil exercise. Each student needs a copy of the game sheet. Students write the strategy to be used to complete the game sheet in the center box, then move around the track applying the strategy in the center to each of the numbers around the track and write their answer in the outer box of the game sheet. (Tokens should be made available for students to use)
This game is ideal for practicing strategies as they are being taught as well as reviewing previously learned strategies.
Source: Guide d'enseignement efficace des mathématiques de la maternelle à la 6e année, p. 80.
Activity 7: Array (Multiplication Facts)
Represent, with students, the basic number facts being studied using arrays.
Collectively create a large poster that illustrates basic number facts.
The poster can be created with different colors.
Ask students to identify patterns and connections between products.
The multiplication table is represented in two ways.
Activity 4: Multiply or Add Game
Number of players : 2
Material 2 dice
Roll the 2 dice, then add or multiply the 2 numbers. If you choose, for example, to add, you must always add and your partner must always multiply. If you choose to multiply, your partner will add. The winner is the one who reaches 12.
If you start first, which operation will you choose and why?
Source : L'@telier - Ressources pédagogiques en ligne (atelier.on.ca)