Teacher to student groups (4 people) Group 1-piece replica watches are invention then, each group provide artificial simulation intended to the members of the group told time.
Teachers give students the same group (4 people), inventor of the first pieces of replica watches and replica watches for each group to devise a set time. Then members of the group told the Times.
The teacher after the original (4) clock invented simulation group, 1 pieces. Then each group the artificial simulation clock to time. Then the group members tell the time.