Ellen Alden, age 8, of Drexel Hill, Pennsylvania, for her question:

How big is an acre?

We can call it area or square measure. In any case, we use the acre to measure the flat surface of the ground. One acre may be an oblong, an oval or any other flat shape. But it always has just enough room to hold 4,840 square yards. And each square yard is a flat square that measures 36 inches on each side. The neatest acre is a perfect square. It has four square corners and each of its four sides is a little bit longer than 69 yards.

Actually, one acre of good land is big enough for a family house, a vegetable garden and an orchard of assorted fruit trees. There also is room for some chickens to lay eggs and a goat to give milk. There is space for a small barn to keep tools and such, a few shade trees and a place for a wondrous outdoor playhouse for the children