MATHS AS PLAY COMENIUS 2011 – 2013 February 2013

1. MATHS AS PLAYCOMENIUS 2011 – 2013February 2013

2. Mathematicsand astronomy Competition for the 4 grade

3. Problem 1 Now the year is2013. In 1543 the Polish astronomer Nicolaus Copernicus proved that the Earth rotates on its axis while orbiting the Sun. How many years ago did it happen?

4. Answer 2013 – 1543 = 470 It happened 470years ago.

5. Problem 2 Make the calculations and you will find out how many years ago the Earth was born. 2 850 400 300 3 940 610 900 2 291 011 200

6. Answer It was born 4 500 000 000 yearsago. 6 791 011 200 2 850 400 300 3 940 610 900 2 291 011 200 4 500 000 000 6 791 011 200

7. Problem 3 The orbital period of Jupiter, the biggest planet in the solar system, is about 4 328 days and nightsand the orbital period of Mars – 682. Compare the data with the orbital period of the Earth.

8. Answer А) 4 328 – 365 = 3 963 days and nights The orbital period of Jupiter is 3 963 days and nights longer than the orbital period of the Earth. The orbital period of the Earth is 3 963 days and nights shorter than the orbital period of Jupiter. Б) 682 – 365 = 317 days and nights The orbital period of Mars is 317 days and nights longer than the orbital period of the Earth. The orbital period of the Earth is about 317 days and nights shorter than the orbital period of Mars.

9. Problem 4 The radius of the Earth is 6 378 km long which is 688 622 km shorter than the radius of the Sun. How long is the radius of the Sun?

10. Answer 6 378 + 688 622 = 695 000 The radius of the Sun is 695 000 km long.

11. Problem 5 Here is a chart with the range of the planets in the Solar system, their radiuses and distances from the Sun. Is it true that: A) The radius of the Earth is 2 978 km shorter than the radius of Mars? B) Venus is 41 000 000kmcloser to the Sun than the Earth? C) The difference between the radiuses of the smallest planet and the biggest one is 69 600 km?

12. Answer A) 6 378 – 3 400 = 2 978 km No! The radius of the Earth is 2978 km longer than the radius of Mars. B) 149 000 000 – 108 000 000 = 41 000 000kmYes! C) 71 820 – 2 420 = 69 600 km Yes!

13. Problem 6 • The orbital period of the planet Venus around the Sun is about 225 days and nights, the orbital period of the Earth is 365 and the orbital period of the planet Mercury is 88. • How many days and nightswill it take to Venus to make 3 orbits, to Mercury – 8 orbits and to the Earth – 2 orbits?

14. Answer 225 . 3 = 675 To Venusit will take 675 days and nights. 88 . 8 = 704 To Mercury it will take about 704 days and nights. 365 . 2 = 730 To the Earth it will take 730 days and nights.

15. Problem 7 • The planets circle around the Sun. The radius of the orbit of the Earth is 150 000 000km long and the radius of the orbit of Venusis 60 000 000 km. • How long is the possible shortest distance between the two planets?

16. Answer 150 000 000 – 60 000 000 = 90 000 000 The possible shortest distance between the two planets is 90 million km.

17. Well done! Congratulations!