The document discusses units from a math and science course for young children. Unit 17 covers ordering, seriation, and patterning. Ordering involves comparing more than two items in a sequence. Seriation refers to ordering specifically. Patterning involves discovering visual, auditory or motor patterns. Unit 18 is about measurement and assigning numbers to compare attributes of volume, weight, length and temperature. Unit 19 discusses measuring time and how children learn sequence and duration, which get applied to personal, social and cultural understandings of time. Key terms are defined for each unit.