Co-ordinate 2B
Overview
This Phlow develops understanding of measuring dimensions of shapes on a coordinate grid where each square has a side length of 1 cm. Students are asked to determine the width or height of rectangles and triangles by counting units across the x- or y-axis.
In the first two tasks, students calculate the width of rectangles, reinforcing how to count units along the x-axis.
The third task introduces a triangle, where students find the width of its base, building flexibility in identifying dimensions across different shapes.
The final task focuses on the height of a rectangle, requiring students to measure along the y-axis.
This sequence strengthens the link between grid units and centimetre measurements, while supporting spatial reasoning and accurate reading of axes.
Prerequisite Knowledge Required
- Co-ordinate 1A – identifying points and axes on a grid.
- Shapes 1 / Polygons 1A–B – recognising basic 2D shapes and their sides.
- Length 1 – understanding centimetres as a unit of measure.
Main Category
Geometry / Measurement
Estimated Completion Time
Approx 6-10 seconds per question. 20 questions total. Total time: 2-4 minute.
Cognitive Load / Step Size
Low to moderate — progresses smoothly from counting along one axis (x) to counting along both (x and y). Cognitive demand rises slightly when switching shapes or axes.
Language & Literacy Demand
Low — questions are short and supported by clear visual grids. Text such as “What is the width?” or “Find the height” is simple and unambiguous.
Clarity & Design
Excellent — each grid uses bold outlines and labelled axes. The 1 cm grid scale makes the link between counting and measuring explicit. Visuals are functional, not decorative.
Curriculum Alignment
Matches Geometry and Trigonometry – Co-ordinate Geometry outcomes in the Irish Mathematics Curriculum:
- Measure distances between points on a coordinate grid.
- Recognise and interpret dimensions of geometric figures using coordinates.
Engagement & Motivation
Moderate — students enjoy the hands-on spatial reasoning and the clarity of counting squares. Provides a practical bridge between geometry drawing and algebraic coordinates.
Error Opportunities & Misconceptions
- Miscounting grid squares (forgetting to start at 0).
- Confusing width with height or misreading the axis labels.
- Overlooking that each grid square represents 1 cm, not 1 unit.
Transferability / Real-World Anchoring
High — applies directly to map-reading, technical drawing, and interpreting coordinate-based diagrams. Builds measurement accuracy used in design and engineering contexts.
Conceptual vs Procedural Balance
Balanced — students practise a straightforward procedure (counting squares) while reinforcing the underlying concept of distance on coordinate axes.
Learning Objectives Addressed
- Measure horizontal and vertical distances on a grid.
- Connect coordinate units to centimetre measurements.
- Identify width and height of common shapes.
- Strengthen spatial reasoning and axis interpretation.
What Your Score Says About You
- Less than 5: You may need more practice linking counting with axis measurement.
- Between 6–7: You can measure accurately but sometimes mix up axes.
- Between 8–9: You’re confident reading and measuring shapes on grids.
- 10/10: Excellent — you can interpret grid dimensions quickly and precisely.