Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Maps and Scales: A map is a flat representation of a larger area. Because we cannot draw the actual size of a place, we use a 'Scale' to reduce distances proportionally. Visually, a map looks like a small drawing where a line might represent a real-world distance of .
Cardinal Directions: Maps are standardly oriented using four main directions: North (), South (), East (), and West (). Visually, imagine a cross: North points to the top edge of the map, South to the bottom, East to the right, and West to the left.
Measuring Distance on a Map: To find the real-world distance between two points, measure the distance on the map using a ruler and then multiply it by the scale factor. If two points are apart on a map with a scale of , the ground distance is .
Grid Systems: Maps are often divided into equal-sized squares called a grid. This helps in locating specific landmarks precisely. For instance, a landmark might be located in grid box , where represents the column and represents the row.
Enlarging and Reducing: When a map or picture is redrawn from a grid to a grid, it looks bigger. The side of the square doubles, but the area becomes times larger. Visually, a small square of fits four times into a larger square.
Landmarks and Symbols: Landmarks are easily recognizable features like a bridge, a park, or a temple used to guide someone. In a map, these are shown as small symbols or icons (like a small blue wave for a river or a green tree for a forest) to save space while providing clear information.
Turns and Angles: Directions can be understood through angles. Turning from North to East is a clockwise turn (a right angle). Turning from North to South is a turn (a straight line). Visually, these turns follow the corners and edges of a square grid.
📐Formulae
💡Examples
Problem 1:
On a city map, the scale is given as . If the distance between a school and a library on the map is , what is the actual distance in metres?
Solution:
- Identify the map distance: .
- Identify the scale: .
- Multiply map distance by scale value: .
- Therefore, the actual distance is (or ).
Explanation:
To convert map distance to real distance, we multiply the units measured on paper by the value assigned to each unit in the scale.
Problem 2:
A square garden with a side of is drawn on a map with a grid. If the map is redrawn on a grid, what will be the area of the garden on the new grid?
Solution:
- Side of the garden on original grid = units ().
- In the new grid, each unit is instead of .
- The new side length in centimeters will be .
- Area of the garden on the new grid = .
Explanation:
When we change the grid size, the number of grid squares occupied stays the same, but the physical measurement of each square increases, leading to a much larger total area.