1. How do you change from one unit ot another in the metric system?

Changing units always involves either multiplying or dividing by a multiple of 10. e.g. To change millimetres to kilometres multiply by 1 000 000.

2. Which units are used to measure the area of a country?

Square kilometres (km2)

3. Now that acres are no longer used as a unit of area, how are the areas of house sections measured?

Land areas are measured in square metres (m2) or hectares.