Reading:
As first grade teachers we encourage our students and their parents to read together every night (or as often as possible). They can read to you, you can read to them, or you can read a story together. 

Try to set aside a specific time and place each day to review your child's school work. 

Encourage your child to tell you in detail about the day's events.   

Be positive about school, and your child's continued efforts to do well. 

Math:
Also, please have your child practice their addition and subtraction facts. 
Flashcards are a great tool for this! There are also many great websites that help students practice these skills as well.