Teach math skills with your child's building blocks. Preschoolers love counting things. Help your preschooler to increase the highest number to which she is able to count by lining up blocks, asking your child to count them, and then increasing the number each time.
Use colored building blocks to help your child practice colors. Point to each block and let her tell you the name of the color. Teach older preschoolers about mixing colors by placing a red block, a blue block and a purple block in a line while explaining how to mix one color with another color to get a whole new color. Repeat the process with the other colors.
Introduce a basic science lesson by using the building blocks to set up a basic science experiment. Let your preschooler predict how many blocks she will be able to stack before the tower of blocks falls down. What will happen when too many blocks are added to the tower? Test the hypothesis.
Encourage your preschooler's social skills by reinforcing the process of sharing. Divide the blocks and build separate structures. As you build, you might each discover that the other has a block better suited for what you are each are building. Ask your preschooler if you might trade a round block for a square one to complete your structure. Reinforce the proper social etiquette as you conduct your trade.
Encourage your preschooler's art skills by using the blocks to make pictures. This also works wonders for the imagination. A square block becomes a picnic table at the park. A round block might be a tree. Help your child's picture making to progress beyond crayons and paper by using the building blocks as a new way to create art.