Page 103 - Mathematics GRADE 9, DE-STREAMED (MTH1W)

o comparing fuel efficiency or energy consumption:
▪ e.g., different vehicles, in different driving conditions
Instructional Tips
Teachers can:
• highlight the concept that rates and ratios, including percentages, describe comparisons;
• emphasize the cross-strand and cross-curricular connections that illustrate real-life applications of
number concepts (e.g., the use of proportions between physical quantities in science, such as describing density as the ratio of mass to volume; the use of rates in data analysis and linear relations; and the use of rates and percentages in financial literacy);
• support students in selecting an appropriate tool or strategy for the problem they want to solve, such as using grid paper or ratio tables.
Teacher Prompts
• How do you know whether a given situation involves rates, percentages, or proportions?
• Describe two different types of situations where knowing the unit rate would be beneficial.
• Is the ratio between the perimeter of a square and its diagonal the same for any two squares?
How do you know?
• Given a cylindrical container that holds 12 L and has a radius of 5 cm, determine the height of the
original container and then find the height of containers that hold double the original volume and 25% more than the original volume.
• Which slope is steeper: 12% or 8 ? How do you know? 50
• How do you know how these two mathematical statements compare, without calculating the answers: 75% of 28 or 28% of 75?
• What are some values that would make the following statement true? $32 is ____% of _____.
• What strategies would you use to determine which of the below is the better deal?
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