Application of Map Skills (Part 1)

Grade 10 · Geography

Semester 2 | Period 4 | Week 22

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Subject: Geography

Semester: 2

Period: 4

Week: 22

School Name: ___________________________
Teacher’s Name: _________________________
Subject: Geography
Grade Level: Grade 10
Date: _____________________
Lesson Duration: 45 minutes
Week & Period: Week 22, Period 4
Topic: Application of Map Skills (Part 1)
Sub-topic: Reducing & Enlarging Maps, Ground Distances & Areas, Gradient of Slopes

 

Learning Objectives

By the end of the lesson, students should be able to:

  1. Define and explain map reduction and enlargement.
  2. Use map scales to calculate ground distances between two points.
  3. Apply scale to determine areas on a map.
  4. Calculate the gradient of a slope from contour information.
  5. Solve practical examples in class.

 

Previous Knowledge

Students already know how to:

  • Identify types of scales (RF, statement, linear).
  • Convert between RF ↔ Statement ↔ Linear.
  • Draw linear scales.

 

Instructional Materials

  • Atlas & topographic maps
  • Ruler, compass, divider
  • Graph paper
  • Chalkboard/whiteboard
  • Projector/slides with worked examples

 

Lesson Development – ABC Model

A – Anticipation (Warm-up / Starter)

Time: 5–7 minutes

Teacher’s Questions:

  1. “If 1 cm on a map = 2 km on the ground, how far is 5 cm?”
  2. “When you zoom in on a map in your phone, what happens?”
  3. “Have you noticed that some maps are bigger or smaller versions of others?”

Learners’ Role:

  • Respond to questions.
  • Recall the role of scale in map drawing.

 

B – Building Knowledge (Main Lesson Body)

Time: 25–30 minutes

  1. Reducing & Enlarging Maps
  • Definition:
    • Reduction – Drawing a smaller version of a map using a smaller scale.
    • Enlargement – Drawing a bigger version of a map using a larger scale.
  • Example:
    • Original scale = 1:50,000
    • If reduced to 1:100,000 → features become smaller (covering larger ground).
    • If enlarged to 1:25,000 → features become bigger (covering smaller ground).

 

  1. Calculation of Ground Distances
  • Formula:

Ground Distance=Map Distance × Scale Factor

  • Example 1:
    RF = 1:100,000
    Map distance = 4 cm
    → 4 × 100,000 = 400,000 cm = 4 km
  • Example 2:
    Statement: 1 cm = 2 km
    Map distance = 7.5 cm
    → 7.5 × 2 = 15 km

 

  1. Calculation of Areas on a Map
  • Method 1: Count squares on graph paper or map grid.
  • Method 2: Use formula when given dimensions.
  • Example:
    Scale = 1:50,000 (1 cm = 0.5 km)
    Measured area on map = rectangle of 6 cm × 4 cm = 24 cm²
    Convert: (0.5 km × 6) × (0.5 km × 4) = 3 km × 2 km = 6 km²

 

  1. Gradient of Slopes
  • Formula:

Gradient=            Vertical Interval (rise)

                             Horizontal distance(run)

  • Example:
    Vertical interval between contours = 100 m
    Horizontal map distance = 2 cm
    Scale = 1:50,000 → 2 cm = 1 km = 1,000 m
    Gradient = 100 ÷ 1,000 = 1:10 (gentle slope)

 

Learners’ Role:

  • Follow worked examples.
  • Solve practice problems in pairs.

 

Practice Questions (in class):

  1. A map has a scale 1:200,000. What is the ground distance if two towns are 8 cm apart?
  2. On a 1:50,000 map, a farm measures 5 cm by 3 cm. Calculate its ground area.
  3. Two contour lines are 50 m apart vertically. On the map, they are 2.5 cm apart. Scale 1:25,000. Find the slope gradient.

 

C – Consolidation (Conclusion & Assessment)

Time: 5–8 minutes

Teacher’s Summary:

  • Enlarging = bigger scale, Reduction = smaller scale.
  • Distances on ground are found using scale × map distance.
  • Areas are found using converted dimensions or grid squares.
  • Gradient = rise ÷ run.

Assessment (Exit Ticket):

  1. Differentiate between reduction and enlargement.
  2. If map distance = 10 cm, scale = 1:100,000, find ground distance.
  3. State the formula for gradient of slopes.

 

Assignment

Part A – Distance

  1. Calculate the ground distance when:
    a) 12 cm on map, scale = 1:250,000
    b) 5.5 cm on map, scale = 1:50,000

Part B – Area
2. A plot of land measures 4 cm by 3 cm on a 1:100,000 map. Find its area in km².

Part C – Gradient
3. The vertical interval between two points = 200 m. They are 5 cm apart on a map of scale 1:50,000. Find the slope gradient.

 

Differentiation / Inclusive Strategies

  • Struggling Learners: Use simple numbers (1 cm = 1 km) for practice.
  • Advanced Learners: Give complex problems with irregular areas.
  • Learners with Disabilities: Provide enlarged maps with bold contours for clarity.

 

Teacher’s Reflection (After Class)

  • Were students able to solve problems step by step?
  • Did they understand slope gradient?
  • What part needs reinforcement next week?