7. Translate the text into English.

Десятичная система нумерации возникла в Индии. Впоследствии её стали называть «арабской», потому что она была перенесена в Европу арабами. Цифры, которыми мы пользуемся, тоже называются арабскими. В этой системе важное значение имеет число «десять», и поэтому система носит название десятичной системы нумерации.

8. Translate the following text.

Here are few amazing prime numbers, these prime numbers were proved by the XVIII^th century.

31

331

3331

33331

333331

3333331

33333331

The next number 333333331 is not a prime number. Whereas it is multiplied by 17×19607843 = 333333331.

9. Solve the following problems.

• Can you put ten sugar lumps into three cups so there is an add number of lumps in each cup?

• Tell me quickly: What time is it when it`s 60 minutes to 2?

• Frederick the frog quite liked Freda the frog who was sitting on the next stone to him on the pond. He began to wonder how many jumps it would take him to land on the same stone as her. The 11 stones were equally spaced in a circle around the pond. Frederick could jump over two stones at a time, landing three away, while Freda could clear one stone in each jump, landing two away. They both jumped simultaneously and Freda always jumped anticlockwise. In which direction should Frederick keep jumping for the quickest rendezvous, clockwise or anti-clockwise?