## Lesson 2

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## Here is the text from the video.Now let’s try some problems with our base ten blocks. If you don’t have your base ten blocks and place value mat pause the video and go get them. Here is 74 minus 7. With your base ten blocks show 74. Pause the video and restart it when you are ready. Here I only have 4 ones and I need to take away 7. I can’t do it so I have to borrow and regroup one of the tens, remember they are called rods. So take one of your rods and if you have the kind that can break apart then break it apart into units. If yours don’t break apart then you will have to trade your rod for 10 ones or units. Pause the program and then on the next slide you can see if yours looks like mine.
This is how your base ten blocks should look. You still have 74 but you should have regrouped so that now you have 6 rods and 14 units. 6 rods is 60 plus 14 units is 74. Now that you have 14 units, you can take away 7. Take away 7 now Did you get 67? That’s great if you did. If you didn’t go back and try it again. Let’s try another one. Here is 53 minus 6. With your base ten blocks show 53. Pause the video and restart it when you are ready. Here I only have 3 ones and I need to take away 6. I can’t do it so I have to borrow and regroup one of the rods. So take one of your rods and either break it apart or trade it in for 10 ones. Pause the video while you do this Now after we regroup we still have 53 but we have 4 rods which equals 40 and 13 ones. Now we can take 6 away from the 13 ones. Pause the program while you take six away Did you get 47? Good Job if you did. If you didn’t you can always start over. Now let’s try subtracting a two-digit number. Let’s try 61 minus 15. First show 61 with your blocks. Pause the video and restart it when you are ready. Since we can’t take 5 from 1 so you will have to regroup. Pause the program and regroup one ten for ten ones. Then press play. Now you should have 5 rods and 11 ones. Now you can take away 15. Pause the video, Take away one rod and five ones and then start the program to see if you got it right Did you get 46? If you did keep going. If not try it again. Here is 50 minus 32. Here there are no ones at all. We have to regroup. Regroup now, pause the program and restart it after you regroup. 50 can be regrouped to be 4 tens, 40, plus 10 ones. Now we can subtract. Take away 32 now You should have 18 left. Next we are going to practice writing our subtraction problems. We have been writing the problems the long way as we show all the steps. Now that you understand how to do subtraction with regrouping, there is a shorter way to write the problems. If you are ready go to the next lesson and we will get started. |