Grade 4 · Unit 8: Location and transformation

Scales and maps

1 cm on the map is how far in real life?

Maps of Bangladesh

A map of Bangladesh fits on one page. Every distance has been shrunk using a scale. The scale tells us how to find real distances.

Using a scale

On this map, 1 cm stands for 10 km. Two towns are 6 cm apart on the map. Real distance: 6 × 10 = 60 km.

Ratio

A scale is a ratio: 1 cm to 10 km. Double the map distance, double the real distance. This is called proportion.

Coordinates

Coordinates give a position with two numbers. Read across first (x), then up (y). A is at (2, 3).

Plotting shapes

Plot points and join them to make shapes. B is 4 squares to the right of A; C is 3 squares above B. Ships and planes use bearings: an angle measured clockwise from north. East is a bearing of 090°.

Ratio problems

A ratio compares two quantities. On a map, 1 cm stands for 20 km. 3 cm stands for 60 km. A drink is 1 part juice to 4 parts water. For 2 cups of juice, use 8 cups of water.

What I learnt

• I can use a map scale.
• I understand scale as a ratio.
• I can read and plot coordinates.