Instructions:
Look at each number carefully and line up the Tens and Ones.
* For addition, add the ones first. If the ones make 10 or more, regroup 10 ones as 1 ten.
* For subtraction, subtract the ones first. If there are not enough ones, regroup 1 ten as 10 ones.
Write the regrouped number in the correct box.
Solve each problem and write the final answer on the line.
Complete all 20 items neatly and independently.