B2.4 Demonstrate an understanding of algorithms for adding and subtracting whole numbers by making connections to and describing the way other tools and strategies are used to add and subtract.
Activity 1: Bull's Eye!
Introduce students to the "Bull's Eye" game. Ask students to keep track of their calculations.
The goal of the game is to form 3-digit numbers that add up to as close to 1000 as possible using cards from 0 to 9.
Materials
- playing cards from which the 10s, jacks and queens have been removed;
- appendix Bull's Eye! - Points scored (2 copies per team of 2).
Directions
Players place playing cards face down in a deck.
Note: The Joker represents any number from 1 to 9. The king represents 0.
In turn, each student:
- draws 6 playing cards from the deck and lays them face up on the table to form 2 three-digit numbers that add up to, but do not exceed, 1000;
Example
- write an equation to represent the sum of these 2 numbers on the sheet Bull's Eye! - Points scored;
- determine the person who has the sum closest to 1000; this person scores one point;
Example
- puts the used cards face down in another pile;
- draws 6 new cards to replace the used ones.
If there are no more cards to be drawn, the used cards must be returned to the pile and shuffled in order to continue the game.
The game ends after 5 rounds.
Each person determines the number of points scored for the 5 rounds. The person who gets the most points wins the game.
Source: Les mathématiques… , Guide pédagogique, Édition révisée, Numération et sens du nombre, 3e année, Module 3, Série 2, Activité 3 - En plein dans le mille, p. 444-446.
Activity 2: More or Less, It's Clear!
Ask students to determine the sum or difference of each equation below in 2 different ways. Ask them to leave a record of their approach.
Source: Les mathématiques… , Guide pédagogique, Édition révisée, Numération et sens du nombre, 3e année, Module 3, Série 2, Activité 3 - En plein dans le mille, p. 447.
Activity 3: Two Make a Pair
Ask students to write 5 additions, which add up to 1000, using all of the following numbers.
Ask students to write 8 subtractions whose difference is 342 using all of the following numbers.
Source: Les mathématiques… , Guide pédagogique, Édition révisée, Numération et sens du nombre, 3e année, Module 3, Série 2, Activité 4 - Les deux font la paire, p. 457-458.