## 1. History of numbers : from natural to complex numbers

•  In this part, the students present details of the history of numbers answering these points :

A. Warm up : Find the most interesting story about numbers or interesting picture or puzzle connected with the topic – it should be short and easy to understand.

B. In that lesson you should answer for at least these questions:

- Where and when the numbers were invented?

- Why 0 and 1 weren’t at first treated as real numbers ?

- When 0 was firstly accepted as a number and why?

- Which numbers came first : negative or fractions?

- Which irrational number is the first known one?

- What was the purpose of accepting the root of -1 When was it done and by whom?

- What are the relations between the sets of numbers: natural, integers, rational, irrational, real and complex and how it refers to actions between numbers.

C. You have to propose some tasks to check

- the understanding of relations between  different sets of numbers,

- the way of use of appropriate symbols,

- recognition of different type of numbers,

- actions between numbers

D. Sum up – propose a poster or happening about the world of numbers. 