Briefly go over the concepts of thousands numbers, hundreds numbers, tens numbers and ones values. First count how many blocks you have. Then count how many blocks are added on. Explain that you begin by adding the thousands numbers together. Then you add the hundreds numbers, tens numbers, and ones numbers together. Then you add all the numbers together to get the final answer. Now show that for the same problem, you can choose to split up numbers to solve in steps by regrouping. In this way, you can solve the problem by splitting the tens numbers into 50 and 20 and the ones values into 2 and 6. Practice the next problem together with the students. Ask the students which method they used to solve the problem. Have the students solve the next two problems on their own. Show the sum 3,850 + 468. Show that the girl adds the hundreds numbers, tens numbers and ones values. Then she adds everything together to get the answer. Now show the boy. He splits the second number up into hundreds numbers, tens numbers and ones values and adds them up in steps to get to 3,850. Have the students solve the next three problems on their own. For the story problem you can discuss the different methods that can be used to solve the problem. The students can solve the next two story problems on their own.

Check whether the students can add to 10,000 by regrouping with the following question:

- Which method do you use to add to 10,000 with regrouping?