Exploring Our World: Junior Cycle Geography · 1st Year · Geographical Skills and Mapping · Summer Term

Map Scales and Symbols

Students will learn to interpret different map scales and common Ordnance Survey map symbols.

• NCCA Curriculum Specifications
• NCCA: Junior Cycle - Geographical Skills
• NCCA: Junior Cycle - Cartography

About This Topic

Ordnance Survey (OS) maps are the essential tools of a geographer, allowing us to represent a complex 3D world on a 2D surface. This topic focuses on the practical skills of map reading using the 1:50,000 Discovery Series. Students learn to use four-figure and six-figure grid references, interpret symbols, calculate distance and area, and understand height through contours and color.

In the NCCA Junior Cycle, 'Geographical Skills' are integrated throughout the three years. Mastering OS maps is not just about passing an exam; it's about developing spatial awareness and the ability to navigate and plan in the real world. Students learn to 'read' the landscape, identifying patterns of settlement and physical features from the symbols on the page.

This topic comes alive when students can physically navigate using maps or use them to solve collaborative 'treasure hunt' challenges in the classroom or school grounds.

Key Questions

1. Differentiate between ratio, linear, and verbal map scales.
2. Explain how to use a map legend to interpret symbols.
3. Analyze why different map scales are used for different purposes.

Learning Objectives

• Compare and contrast ratio, linear, and verbal map scales, explaining the mathematical relationship between them.
• Analyze the purpose of a map legend and explain how specific symbols represent geographical features.
• Calculate straight-line and curved distances on an Ordnance Survey map using the provided scale.
• Classify different map scales based on their suitability for various geographical investigations, such as local area surveys versus national overviews.

Before You Start

Introduction to Maps

Why: Students need a basic understanding of what a map is and its purpose before learning about specific map features like scale and symbols.

Basic Measurement Skills

Why: The ability to use a ruler and understand simple units of measurement is essential for working with linear and ratio scales.

Key Vocabulary

Map Scale	The ratio between a distance on a map and the corresponding distance on the ground. It shows how much the real world has been reduced to fit on the map.
Ratio Scale	A map scale expressed as a ratio, such as 1:50,000, meaning one unit on the map represents 50,000 of the same units on the ground.
Linear Scale	A scale shown as a line marked with distances, allowing direct measurement of distances on the map using a ruler.
Verbal Scale	A map scale stated in words, for example, 'One centimetre represents one kilometre'.
Map Legend	A key that explains the meaning of the symbols, colours, and patterns used on a map.

Watch Out for These Misconceptions

Common Misconception

Contour lines that are far apart mean the land is very steep.

What to Teach Instead

It's the opposite: close lines indicate a steep slope, while far apart lines indicate flat or gently sloping land. A 'walking the lines' exercise where students use their hands to show the slope helps correct this visual error.

Common Misconception

The top of the map is always North.

What to Teach Instead

While usually true for OS maps, students should always check the compass rose. Using a real compass in the classroom to orient their maps helps them understand the relationship between the paper and the real world.

Active Learning Ideas

Inquiry Circle: The OS Treasure Hunt

Students are given a list of 6-figure grid references for a specific map. Each reference leads to a 'clue' (a symbol or feature). They must work in pairs to find all the clues and solve a final geographical puzzle.

45 min·Pairs

Simulation Game: 3D Contour Modeling

Using playdough or stacked cardboard, groups build a 3D hill and then 'slice' it to create their own contour map. They then swap maps with another group to see if they can identify the steepest and flattest parts.

50 min·Small Groups

Think-Pair-Share: Route Planning

Students are given a starting point and a destination on a map. They must plan the 'easiest' route for a hiker, discussing with a partner why they chose to avoid certain steep contours or marshy symbols.

25 min·Pairs

Real-World Connections

• Cartographers at Ordnance Survey Ireland use various map scales to produce detailed maps for hikers, emergency services, and urban planners, ensuring accuracy for navigation and land management.
• Archaeologists use large-scale maps, often with detailed symbols, to record the precise locations of artifacts and features at excavation sites, helping them reconstruct past landscapes.
• Pilots and navigators rely on understanding map scales and symbols on aeronautical charts to plan flight paths and identify landmarks for safe navigation.

Assessment Ideas

Quick Check

Provide students with a section of an Ordnance Survey map and a map legend. Ask them to identify three specific symbols and explain what they represent. Then, ask them to calculate the distance between two points using the linear scale.

Exit Ticket

On a small card, have students write down one example of a situation where a 1:50,000 scale map would be most useful, and one situation where a 1:10,000 scale map would be better. They should briefly explain their reasoning for each.

Discussion Prompt

Pose the question: 'Why do mapmakers choose different scales for different maps?' Facilitate a class discussion where students share their understanding of how scale affects the level of detail and the area covered by a map.

Frequently Asked Questions

What are the best hands-on strategies for teaching OS maps?

The best strategies involve moving from 3D to 2D. Building physical models of hills and then drawing the contours (or vice versa) helps students visualize height. Map-based 'treasure hunts' or 'escape rooms' that require using grid references and symbols to solve puzzles also turn a technical skill into an engaging, collaborative game.

What is the difference between a 4-figure and a 6-figure grid reference?

A 4-figure reference identifies a single 1km square on the map. A 6-figure reference is more precise, identifying a specific 100m square within that larger grid square.

How do I calculate the distance between two points on a map?

You can use a piece of string or the edge of a sheet of paper to measure the distance on the map, then compare it to the scale bar at the bottom to find the real-world distance in kilometers.

What do the different colors on an OS map represent?

Generally, green represents forest/woodland, blue represents water, brown represents contour lines (height), and red/orange represents main roads.