In grade 2, students learned to tell time to the nearest five minutes and recognized that there are 60 minutes in 1 hour. In grade 3, they learned to tell time to the nearest minute and to measure intervals of time. Students may also know that there are 60 seconds in a minute. In this lesson, students see the relationship between hours and minutes, and between minutes and seconds, in multiplicative terms. They then use their new insights to convert hours into minutes, and minutes into seconds.