**Part 1**: Follow along with your instructor. In the first now of problems, add the blocks together. Before you write your final answers, remember to combine (regroup) the ones into groups of 10 so that the blocks are easier to count. Then solve the related problems in the second tow of problems. Remember, only one digit (0, 1, 2, 3, 4, 5, 6, 7, 8, or 9) can be written in each place value column
**Part 2**: Add. Most of these problems require regrouping.

### Worksheet for the lesson

Lesson 4 Double-digit addition worksheet pdf download