Key Spelling is a series of graded activity books containing puzzles & problems that will reinforce children's essential spelling skills & knowledge. Key Spelling Book 1 covers: single consonant sounds made by more than one letter (for example 'ch' 'sh' & 'th') vowel sounds made by more than one letter (for example 'ea' & 'ow') & letter blends such as 'st' 'ng' & 'cr'.