Final answer:
Jolie's area model for 5 × 20 resulted in an incorrect product of 80 instead of 100. The error is likely that she made fewer than 5 rows, which corresponds to She made fewer than 5 rows.
The correct answer is C.
Step-by-step explanation:
The student's question refers to an area model created to solve a multiplication problem, specifically 5 × 20. However, the result given by Jolie is incorrect because 5 multiplied by 20 equals 100, not 80. When dealing with an area model, one must make the correct number of rows and columns that correspond to the factors in the multiplication problem. Each row represents a unit of one factor, and each column represents a unit of the other factor. Without seeing the model, we can deduce the mistake
- If she counted the total number of squares incorrectly, it suggests a simple arithmetic error in tallying the squares.
- If she made more than 20 columns, she would be representing a number larger than 20 for the second factor, which would result in too large a product.
- If she made fewer than 5 rows, she would be representing less than 5 for the first factor, which would produce an incorrect product that is too small.
- If she made more than 5 rows, she would be adding additional units to the first factor, which would also result in a product that is too large.
Based on this, the correct option would be the one that explains why the product is smaller than it should be. Since Jolie's product is 80 and not 100, the error is that she made fewer rows or columns than required for one of the factors. Therefore, the correct answer must either be (b) She made more than 20 columns, or (c) She made fewer than 5 rows. Since the product is too small (80 instead of 100), the most logical error would be making fewer than 5 rows (c).