Final answer:
Aiden should use the grid model with 100 squares where 16 squares are shaded, as this provides a direct percentage of 16% without requiring further calculations.
Step-by-step explanation:
A student named Aiden needs to find the percent of shaded squares in a bar diagram. The most straightforward model to use would be one where the total number of squares represents a quantity that is easy to convert into a percentage.
Among the options provided, using a grid model with 100 squares lets us find percentages conveniently because each square represents 1%. Since Aiden has a model where 16 squares are shaded, it is easiest to see that 16% of the grid is shaded because 16 out of 100 squares provide a direct conversion to percentages. For the options with different numbers of shaded squares (but still with a total of 100 squares), it would mean that different percentages of the grid are shaded, corresponding respectively to 60%, 80%, and 96%.