MYP 2Year 8Term 1
Ratio and Proportion
Number
Statement of inquiry
By understanding relationships and equivalence between quantities, we can use ratios and proportional models to compare, scale, and convert values accurately.
Assessed against
The MYP criteria this unit is marked against.
- Knowing and Understanding
- Communicating
- Applying Mathematics in Real-life Contexts
What this unit covers
The sub-topics taught, in the order the department teaches them.
- 8.2.1 Scale copies, similarity, and scale factor
- 8.2.2 Understand ratio
- 8.2.3 Simplify ratio
- 8.2.4 Express ratio in the form 1:n
- 8.2.5 Compare ratio and fractions
- 8.2.6 Direct proportion
- 8.2.6 Conversion graphs
- 8.2.7 Finding the constant of proportionality
- 8.2.8 Scale diagrams
- 8.2.9 Using map scales
20 objectives
Learning objectives
What students should be able to do by the end of this unit.
Ratio and Rates
0 / 8 ticked
Tick to track on this device. Saved here only — your teacher does not see it.
- Define and apply the concept of a ratio in real contexts.
- Identify and use equivalent ratios.
- Simplify ratios, including ratios involving different units.
- Share an amount in a given ratio.
- Understand and calculate unit rates.
- Find a given percentage of a quantity.
- Find the whole given a percentage part (reverse percentage).
- Calculate percentage increases and decreases.
Proportions
0 / 6 ticked
Tick to track on this device. Saved here only — your teacher does not see it.
- Define a proportional relationship.
- Test whether two quantities are in a proportional relationship using a ratio table.
- Determine the constant of proportionality.
- Write an equation of the form y = kx for a proportional relationship.
- Graph proportional relationships and interpret the gradient as the constant of proportionality.
- Apply direct proportion to solve word problems (recipes, distance-time, costs).
Scale and Similarity
0 / 6 ticked
Tick to track on this device. Saved here only — your teacher does not see it.
- Create and interpret scale drawings.
- Understand and use the concept of scale factor (linear).
- Use map scales to calculate real distances.
- Convert between scale lengths and real lengths in mixed units.
- Recognise similar figures and find missing sides using the scale factor.
- Understand that area scales by the square of the linear scale factor.
Review pack
Curated revision materials parents and students can download.
A review pack for this unit is being prepared.
MYP framing
- Focus ATLs
- Communication: Represent ratios using tables, graphs, and equations
- Self-Management: Choose efficient strategies and check results
- Key concepts
- Relationships – how quantities change together
- Equivalence – maintaining value when scaling or converting
- Models – ratios, graphs, and diagrams as representations
- Global context
- Globalization & Sustainability: Ratio and proportion help us compare quantities fairly, scale objects accurately, and interpret real-world information such as maps, models, and conversions.
- Community engagement
- Using map scales and scale drawings
- Comparing real-life ratios (recipes, models, maps)
- Peer explanation of proportional reasoning