We have the following:
The area is
[tex]A=L\cdot W[/tex]L (long) is 24 inch and W (wide) is 18 inch, replacing:
[tex]\begin{gathered} A=24\cdot18 \\ A=432 \end{gathered}[/tex]The area is 432 squares inch, therefore:
[tex]\frac{432}{1}=432[/tex]Therefore a total of 432 1-inch squares can be cut