When the hour hand is pointing between two numbers, the number of hours is given by the smaller of the two numbers. For example, an hour hand between 4 and 5 indicates 4 hours (and some minutes). The minute hand pointing at 12 indicates a full hour with no minutes to be counted.

What does it mean when the hour hand is in the middle of two numbers?

When the hour hand is between two numbers, it tells you we are between those two hours. The short hand or hour hand makes one full rotation around the dial in 12 hours.

What is the time when the hour hand is between one and two and the minute hand is on three?

On this clock, the hour hand is between two and three. The clock shows the time as 2:45. Remember that the hour hand has not reached three yet. So it's before three o'clock.