› worksheets › grade_3Free Printable Math Worksheets for Grade 3 - Homeschool Math All worksheets come with an answer key placed on the 2nd page of the file. Mental addition. Complete one hundred (missing addend) Add two 2-digit numbers - one addend is a whole ten; Add two 2-digit numbers - one addend is a whole ten - missing addend; Add a 1-digit number to a 2-digit number; Add a 1-digit number and a 2-digit number - missing ...