Explain to the students in your classroom the concept of texture. Relate to them that all materials and object possess their own texture and can be differentiated by it. For example, smooth as silk, rough like tree bark and hard as stone.
Pass around a variety of different objects that all have different textures. Allow the students to feel the objects in their hands and ask them to work in groups to come up with a description of the item's texture. Save a few items of the objects for later in the lesson. After the groups have worked together, have them compare their descriptions with the other groups in the classroom.
Instruct each group to assign a recorder to write for the next part of the lesson. Hold up each of the remaining items that you saved, one by one. Ask the groups to work together to hypothesize what the texture of each item will be. They will use the information that they gathered by feeling the first set of items. After they have come up with answers, have them again share with the class what they think.
Pass around each of the remaining items to the groups and allow them to compare their hypothesis with what the texture actually feels like. This activity can keep going by naming different objects and asking the groups what the texture would be. For example, spaghetti might be slimy and the fur on kittens would be soft. You can make the items harder or easier to guess depending on the grade level.
Assign three textures for the students to find at home for homework. Ask them to look for items that are small enough to bring into class to share. You could assign rough, smooth and soft or any three that you feel would be appropriate for you students' age level.