These addition worksheets start with teaching kids how to add single digits. There is no regrouping in those worksheets so kids will quickly build their math fact addition fluency. They will still be challenged with the pages that include a missing addend, and that is a great way to get them ready for subtraction. Then introduce them to adding more significant numbers, tens, and finally regrouping addition. Some kids may need extra practice addition worksheets, while other kids excel. For those kids advancing, try the more challenging sheets.