Add 1 within 10: Vertical Addition - Math Worksheets - SplashLearn Every 1st graders needs this worksheet to master addition facts. Aid your child on their learning journey as they practice with fluently add within 10. ... Teachers, Use for Free. Home > Worksheets > Math Worksheets > Add 1 within 10: Vertical Addition. Print. Every 1st graders needs this worksheet to master addition facts. Aid your child on ...