3條中一數學題（Estimation）

1. How can we estimate the total number of residents of a building?
Write down the method.

A. Count the number of residents of one storey first, then multiply it
by the number of stories in the building.

2. Is it possible to find out the exact number of students in all the
primary and secondary schools in Hong Kong? Explain it briefly.

A. It is impossible to find out the exact number of students in all the
primary and secondary schools in Hong Kong because there are so
many students and schools.

3. Suggest two strategies to estimate the value of the expression
103+152+143+128+175.

A. a. round off
103+152+143+128+175
=100+150+140+130+180
=700

b. translation strategy
103+152+143+128+175
=103+152+175+142+128
=430+270
=700