To convert 50 miles per hour (mph) to miles per minute (mpm), we need to determine the appropriate conversion factor for time units from hours to minutes.
Given the expression:
[tex]\[
\frac{50 \text{ miles}}{1 \text{ hour}} \times \frac{1 \text{ hour}}{\square \text{ minutes}}
\][/tex]
We need to identify the number of minutes in one hour so that the hours cancel out, leaving us with miles per minute.
We know that:
[tex]\[
1 \text{ hour} = 60 \text{ minutes}
\][/tex]
Therefore, we can replace the box with this value:
[tex]\[
\frac{50 \text{ miles}}{1 \text{ hour}} \times \frac{1 \text{ hour}}{60 \text{ minutes}}
\][/tex]
This conversion correctly converts the units and allows us to go from miles per hour to miles per minute. Thus, the value to be entered in the box is:
[tex]\[
\boxed{60}
\][/tex]
