It's crucial to understand addition facts. Students who struggle with addition facts also have difficulty with related ideas like subtraction, word problems, addition with larger numbers, etc. A fantastic tool to help students in mastering addition facts is to use addition facts within 20 worksheet. This worksheet is about practicing with the horizontal format in which numbers are written side by side. To develop flexibility with numbers and operations, students need to have enough practice in this format and not just rely on the vertical/column method.