Explain that each cube always contains 1,000 blocks, each sheet 100 blocks and each row 10 blocks. That is how you can quickly count how many blocks you see in the image. Then show the problem 7,930 - 120. Count the blocks on the page together. Count how many you have in total, and then how many are taken away and how many blocks you have left. Discuss solving the problem 3,997 - 564 = in the same way. Afterwards, have the students solve some problems on their own. Then show the number line and explain that you can solve the problem 5,758 - 631 by first subtracting the hundreds numbers, then the tens numbers and finally the ones values. Next, discuss the different ways to solve 3,890 - 670 and have the students solve the next few problems on their own. Finally, discuss the steps to solve a story problem. First determine what type of problem it is and what numbers you need, then state the problem and solve it. Discuss the problem about the popsicles together and have the students solve the next problem on their own.
Check whether the students can subtract to 10,000 without regrouping by asking the following question:
- Which method do you use to solve this problem in steps? (2,230 - 130 = ...)