Let a large class of children and a small class of children enter the classroom and let the children compare who is taller and shorter. Ask the children to say: Big brother is tall and little brother is short.

2. Observe that the big picture is taller and shorter.

3. Guide children to find that height comes from comparison.

The teacher took out two plastic flowers with different heights and put them on different horizontal planes. Let the children observe which flower is tall and which flower is short. The teacher concluded: To compare the heights of two objects, we should put them on the same horizontal plane.

4. Guide children not to be affected by the size and shape of objects, and classify them according to the height of objects.