Use card stock to create 40 flashcards. Draw a big or small shape on each flashcard. Use shapes that preschoolers are familiar with such as circles, triangles, squares, rectangles, hearts and stars. Give each child 20 cards and have them place their decks face down on a table. Have them simultaneously turn over one card from their decks. The child with the bigger shape wins the two cards. If both cards display small shapes or both display big shapes, the children place the cards in a separate pile and draw again. After turning over all 20 cards, the child with the most cards wins. Make the game more challenging by using flashcards with big objects such as cars, houses, airplanes and trees. Use small objects such as marbles, candy, pennies and tacks. Ask the children to determine which objects are bigger in real life.
Collect paper towel rolls and cut them to various heights. Cover the rolls with contact paper or wrapping paper. Ask your preschoolers to arrange the rolls from tallest to shortest. Let them also practice arranging them from shortest to tallest. Create a challenge by timing the children as they line up the rolls. When they have developed proficiency using the paper towel rolls, help the children line themselves up from tallest to shortest.
Demonstrate how a balance scale works, then let your preschoolers explore weighing items. Bring in a variety of objects such as an apple, book, toy car and penny. Show the children two objects and ask them to predict which one is heavier. Ask volunteers to place each object on the scale. Discuss whether or not the children's predictions were correct. Have the preschoolers choose other items from around the room and determine which ones are heaviest.
Teach preschoolers the concepts of more and less using graphs. Write a simple question such as, "Do you like chocolate or vanilla ice cream?" on a sentence strip. Place the sentence strip in a pocket chart. Write the words "chocolate" and "vanilla" on index cards and place them in the pocket chart, creating two columns. Give the children index cards and ask them to answer the question by placing their cards in the appropriate columns. When the graph is complete, encourage the children to use the words "more" or "less" when describing the results. Introduce the word "equal" when appropriate.