This is what we did: Divide children into small groups and give each group a marker to use as a reference object, a tray marked "Shorter," a tray marked "Longer," and an assortment of other objects. Direct children to sort the objects onto the correct tray according to whether they are shorter or longer than the marker. Invite children to find other items to add to each tray. Circulate and encourage children to use the words shorter and longer. Prompt them to explain their strategies by asking:How did you know the ___________ was longer (shorter) than the marker? Sample answer: I lined them up. Have children show each other how to line up the end of each object with the end of the reference object, and ask them to explain why this is important. GMP6.1, GMP6.3, GMP6.4
Children sort objects as longer or shorter than a reference object (such as a marker).
Next change the reference object to a large paper clip. Have children clear the trays and re-sort the same classroom objects based on how they compare to the paper clip. Promote discussion about why some of the objects are now on different trays. If time permits, change the reference object to an object that is longer than the marker. Again, discuss why objects are on different trays. GMP6.1
Conclude by asking children to turn to a partner and use two objects from their trays to show and to explain how their lengths can be compared. GMP6.1 Place the materials in the Math Center for children to continue to practice comparing lengths. See Extra Practice and Activity Card 22.