What is the area of a circle with a diameter of 10 millimeters? Estimate the area to the tenths place using 3.14 for pi.

The radius of the circle is half of the diameter, so the radius is 5 millimeters.

The formula for the area of a circle is A = πr^2.

Plugging in the values:
A = 3.14 * 5^2
A = 3.14 * 25
A = 78.5

Therefore, the estimated area of a circle with a diameter of 10 millimeters is approximately 78.5 square millimeters.