Math hounds may simply enjoy ferreting out the pattern in a number string: 1, 2, 3, 5, 8, 13, 21, 34, . . . The exercise becomes much more fascinating, though, when those numbers pop up in the real world. Here Campbell uses color close-ups of flowers, fruit, and fauna to show how numbers from that series—known as Fibonacci numbers—appear as the number of petals on a flower, the number of spirals on a pineapple or sunflower, the curve of a nautilus shell. Her explanation is simple and patient, working first through the equation, which always adds the last two numbers to obtain the next in the sequence, and then offering a visual example from nature. When the details become a bit too eye-boggling to readily discern, she adds color or superimposed numbers to help highlight dense spirals (though a few still leave room for argument). Although teaching and reinforcing the Fibonacci pattern is of main importance, Campbell also makes it very clear that not all numbers in nature conform to this pattern, and that although the sequence bears Fibonacci's name, the pattern was well known in India before he wrote about it. Math teachers will appreciate the clarity of presentation, and the appended glossary and related miscellanea. Children who are ready to move beyond counting books and into brain-tickling areas of mathematics will welcome this introduction.