While numbers are part of mathematics and thus independent of language, numerals, also known as number words, are a linguistic concept which depends on the language under consideration. Put simply, numerals are the words and phrases which describe numerical quantities, classified according to purpose. Among other types there are cardinal numerals ("one", "two", "three", etc.), ordinal numerals ("first", "second", "third", etc.) and fraction numerals (e.g., "one third", "three quarters"). The corresponding grammar is concerned with the declension (if any) of numerals and the rules to form larger numerals from smaller ones. We shall see that there are many differences between the Spanish and the English language.