Learning to count objects is an important preschool skill, as it essentially forms the basis of all math learning. Have your preschooler count objects as you take them to the table. Instruct him to count out dishes, silverware, cups and napkins and place them in the center of the table in preparation for another activity. Assist your preschooler in keeping a running total of all the items placed on the table. You also can remind her to count items as you both clear the table, wash the place setting pieces and return them to cabinets and drawers.
Being able to place like objects in groups is another preschool math lesson. Once the place setting pieces are in the middle of the table, have your preschooler group the plates together, the spoons, forks, cups and so on. After the groups have been formed, ask your child to count the items in each group. Then see if he can rearrange them in different groups, perhaps based on color or the material of which they're made.
When it is time to remove the place settings from the table, try a little visual addition and subtraction with your child. For instance, if you have four plates, place two side by side and the other two side by side. Point to each group as you say, "What is two plus two?" Allow your preschooler to figure out the totals for various groupings. As you remove items from the table, create subtraction sentences. For instance, ask a question like, "If there are five forks, and you take three to the sink, how many forks are left?" Summarize with a subtraction sentence: "Five minus two equals three."