A monomer is essentially a small molecule which combines with another molecule of the same kind to form a macromolecule. When two or more number of monomer units react together they form a polymer through a process known as polymerization.
Carbohydrates are polymers made of monomers units which are simple sugars. The chemical formula corresponds to that of glucose. Starch which is a carbohydrate is formed by the polymerization of glucose.
