These are the task cards I created to use in my fourth grade classroom. Due to the concept, they could be used in other grades as remediation or extension.
Included skills are:
~Explaining the steps to add and subtract larger numbers
~Adding and subtracting larger numbers
~Creation of real-world problems using addition and subtraction
~Filling in missing digits (They love this!)
You could use these as independent practice, a group activity, an assessment, end of year test review, or as an early finisher option.
I hope your class find these as useful as mine does!