Circles for Mac

From Polymath Love Software:

The program contains thirty-two pre-made circle area problems, and thirty-two pre-made circumference problems. For each problem the students gain understanding of radius and diameter by manipulating the size of an on-screen circle. Each area problem illustrates the meaning of the square of the radius. Each circumference problems illustrates the ratio (pi) between diameter and circumference. The relevant California math standard is included in the help window.