How is the entry of a matrix identified

In order to identify an entry in a matrix, we simply write a subscript of the respective entry's row followed by the column. ... One way to remember that this notation puts rows first and columns second is to think of it like reading a book. You always read sideways first, just as you always write the rows first.

Sample Response: When given the diameter, divide it in half to find the radius measure. Then, substitute the radius measure into the formula. Cube the radius and multiply by 4/3. Write the result followed by pi and the label for the units.