Barbara Holseid, age 11, of Perry, Tnwa, for her question:

How do they figure the number of days in a year?

The year is the time it takes our planet to orbit the sun. We can figure this from the changing seasons and in accurate detail from the position of the sun and the heavenly bodies, As it orbits, the earth rotates on its axis, giving us day and night.

On each orbital trip, the earth makes 365 complete turns around its axis, plus part of a 366th turn. For three years, we count 365 calendar days. On the fourth year we gather up the four partial turns and, adding one extra day to the calendar at the end of February, we have a leap year.