1. Use complete sentences when writing your answers.

2. A. The diameter of the Earth at the equator is: 12,742 km (information taken from table, page 11).

3. B. The diameter of the Moon is 3475 km.

4. C. The mathematical equation to describe how many times smaller in diameter the Moon is than Earth is: 3475 km (Moon’s diameter) / 12,742 km (Earth’s diameter) = 0.27, or ¼ the size of Earth

5. D. The distance from Earth to the Moon is 384,400 km

6. E. The mathematical equation that describes how to measure the distance from Earth to the Moon using Earth’s diameter as a unit of measure is: 384,400 km / 12,742 km = 30 Earth diameters from Earth to the Moon

7. F. The diameter of the Sun is: 1, 391, 016 km

8. G. The mathematical equation that describes how many Earth diameters equal the Sun’s diameter is : 1,391,016 km / 12,742 km = 109 Earth diameters

9. H. The Sun appears to be the same size as the Moon in the Sky because the Sun is about 400 times farther away from Earth than the Moon is from Earth. The Sun is also 400 times larger than the Moon. 1,391,016 km / 3475 km= 400 149,600,000 km / 384,400 km ~ 400

10. I. It takes Earth 365 ¼ days to orbit the Sun, and our calendar year is 365 days long. Every year we gain ¼ of a year (6 hrs) and 4 times 6= 24 hours, or one day. ¼ + ¼ + ¼ + ¼ = 1 day

11. J. Since the Moon used in 1.1 is slightly more than a quarter the size of Earth, the 3.5 cm sphere is the only one that is ¼ the size of the 12 cm Earth model.

12. K. The model Sun would have to be 13 m in diameter. The equation would be: 109 x 12 cm= 1308 cm 1308cm / 100 cm= 13 m