1. How many small disks with a diameter of 2 cm can be cut out on a rectangular iron sheet with a length of 13 cm and a width of 4 cm? (error-prone)

The area of a square with the radius of a circle as the side length is 60 square centimeters. What is the area of this circle?

3. The radius of the big circle is equal to the diameter of the small circle, the ratio of the circumference of the big circle and the small circle is (), and the ratio of the area is ().

a . 2: 1 b . 4: 1 c . 1:2d . 1:4

4. A book is *** 100 pages. On the first day, Xiao Ming read two-fifths of the whole book, and the next day, he read a quarter of the whole book. Which page should he read on the third day? (error-prone)