Rather than find a word for 'x', some authors rely on roman numerals, stating ‘x’ is for ten. In addition to not reinforcing the letter-sound, this strategy requires its readers to have a specialized knowledge, which younger children, who are the likely intended audience of these works, would not have. As an alternative approach, this is perhaps the least effective in teaching the phonics of the letter ‘x’ to young readers, who seem to be the audience of these titles featured below.