Processes 8. Priactices using 12 cubes for the bottom layer and 10 cubes for the top layer. She said that the volume of the composite figure was \( 12 \times 10 \), or 120 cubic centimeters. Find and correct her error.

The error lies in the calculation of the volume of the composite figure. To find the correct volume, you need to calculate the total volume by finding the volume of each layer separately and then adding them together. The bottom layer consists of 12 cubes, and the top layer consists of 10 cubes, which should be calculated as \( 12 + 10 = 22 \) cubes in total. Given that each cube has a volume of 1 cubic centimeter, the correct volume is 22 cubic centimeters, not 120 cubic centimeters as she initially calculated. For future similar problems, remember that when dealing with composite figures, it’s essential to calculate the volume of each part separately and then sum them. A common mistake is multiplying the number of cubes instead of adding them when considering different layers or sections within a composite figure, so always double-check the operations you are using.