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 player:
- draws six playing cards from the deck and lays them face up on the table to form two 3-digit numbers that add up to, but do not exceed, 1000;
Example
- writes an equation to represent the sum of these two numbers on the Bull's Eye! sheet and the points scored;
- the players determine who has the sum closest to 1000; this player scores one point;
Example
- The players put the used cards face down in another pile and draw six 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 five rounds.
Each player determines the number of points they scored for the five rounds. The player with the most points wins the game.
Source: translated from Les mathématiques…un peu, beaucoup, à la folie!, 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 two different ways. Ask them to record their strategies on the chart.
Source: translated from Les mathématiques…un peu, beaucoup, à la folie!, 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 addition equations, which add up to 1000, using all of the following numbers.
Ask students to write 8 subtraction equations whose difference is 342 using all of the following numbers.
Source: translated from Les mathématiques…un peu, beaucoup, à la folie!, 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.