Simply by playing, children can build skills in addition, subtraction, story problems, measurement, telling time, long and short vowels, nouns and verbs, and reading comprehension. Skill Sharpeners Math and Phonics Fun is a smart way to sharpen the minds of first-graders, helping young learners strengthen many basic skills and concepts while having fun and building confidence. The concepts in these activity books are taken from several key points in the Common Core State Standards for the first grade.