Cut the flaps off of the back of a cardboard box. Then cut a square in the center of the front about one foot by one foot to make the "Mystery Box" front opening. Glue construction paper onto the outside of the box and let it dry. Tape a 1 1/3 foot by 1 1/3 foot piece of material onto the inside of the box at the top of the hole to make a curtain. Write the words "Mystery Box" on the outside of the box with a marker.
Place the wooden shapes and the plastic square, the ball, the can, the toy pyramid and the funnel into the large paper bag. Tape geometric shape chart to the board that shows each shape and the name of the shape. Ask your students to sit in a circle. Place the paper bag and the mystery box next to your chair and sit down.
Pull the first wooden object out of the bag and point to it on the chart. Tell your student its name ("This is a cube) and have them repeat it. Explain how the shape looks and feels ("This cube has flat sides, corners and edges and all the sides are the same size.") then put the shape on the floor. Continue pulling out the rest of the shapes and discussing the name of the shape and how each shape looks and feels ("The circle is curved with no flat sides or edges.").
Ask a student to reach into the bag and pull out an object (the plastic square, the ball, the can, the toy pyramid or the funnel). Ask them if the object has curves, edges, or sides that are the same size. Tell the student to match the object that they choose with a wooden shape on the floor. The other students can give hints if necessary. Continue this activity until all the objects in the bag have been matched with the wooden shapes on the floor.
Pick up the wooden blocks and put them back in the paper bag but leave the everyday objects on the floor. Put the "Mystery Box" in your lap and secretly place two or more of the objects from inside the bag (e.g. the cube, the sphere and the pyramid) in through the back of the box so that the children cannot see them. Call one student up at a time to reach inside the "Mystery Box" and by just using his or her hands find the shape you ask for (e.g. "Find the cube. It has flat sides that are the same size, edges and corners or vertices.") Ask them to match the wooden shape with an everyday object on the rug. Continue this activity until all the blocks and objects have been matched.