There are other sources for worksheets also. You can find many public schools and private schools which will provide free worksheets for you if you buy textbooks from the school.
Worksheets also, when used properly, provide both the students and parent / tutor immediate feedback as to the child's progress. This means they can be used to point out areas where the student needs further reinforcement.
Review subtraction of 2 numbers whose sums would be 18 or less
Homeschool worksheets are a vital part of the student's homeschool experience. They allow the child to test his or her knowledge, and they offer them a practical application for their learning.