C2.1 Identify quantities that can change and quantities that always remain the same in real-life contexts.
Skill: Determining Which Quantities Change and Which Remain the Same in Daily Life
Students live in a changing world. Understanding that change is a part of life and that most things change over time (for example, each year their height and weight increase and their feet grow in length) is an important aspect of algebraic thinking.
The observed changes can be described qualitatively (I am taller than last year, my hair is longer, it is colder now than this morning) and quantitatively (I have grown 2 cm this year, the temperature has dropped 6°C in 3 hours).
Source: translated from Guide d’enseignement efficace des mathématiques de la maternelle à la 3e année, Modélisation et algèbre, Fascicule 1, Régularités et relations, p. 21.
It is also important to have students observe, in their daily lives, that there are quantities that do not change. This awareness will help them better understand the concept of constancy later in their learning.
Identifying quantities in real life that stay the same and those that can change will help students understand the concept of variability.
Source: Ontario Curriculum, Mathematics Curriculum, Grades 1-8, 2020, Ontario Ministry of Education.
Knowledge: Constant
Quantities that do not change are called constants.
Knowledge: Variable
Quantities that can change, or vary, are referred to as variables.
Source: Ontario Curriculum, Mathematics Curriculum, Grades 1-8, 2020, Ontario Ministry of Education.