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LearningTranscript
00:00Hey kids, it is good to see you guys.
00:09I am in outer space to learn about adding large numbers.
00:13These numbers are big, so I'm going to need your help.
00:20Let me bring my board over and we can learn how to add and subtract large numbers.
00:28Here we have two problems, one is addition and the other is subtraction.
00:33Let's work on the addition problem first.
00:37Let's solve this problem using our base 10 blocks, ok?
00:43Here on top we have 126 and below we have 57.
00:47We need to add these together.
00:50To do this we start with the ones blocks.
00:52We combine all of the ones blocks, the tens blocks and the hundreds blocks together.
01:00Now we add them starting with the ones.
01:02We have 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13.
01:12We have 13, but when we get to 10 we need to trade the 10 ones for a tens block.
01:19Now how many ones do I have?
01:233, I have 3 ones.
01:27Now we count the tens.
01:28We have 1, 2, 3, 4, 5, 6, 7, 8.
01:34So we write the 8 in the tens place.
01:38Now we look at our hundreds place.
01:40How many hundreds blocks do we have?
01:431, so we put the 1 down here.
01:48If we take a look back at the ones place we can see that we added 6 plus 7.
01:52We know that 6 plus 7 is 13 and if you recall once we had 10 ones we traded it for a tens
01:58block.
02:00So I put the 1 in the tens column.
02:03Looking at the tens place numbers we have 1 at the top plus 2 plus 5 which gives us
02:098 and we have the 100.
02:12So the answer is 183.
02:14Amazing job guys!
02:22Now let's go to the subtraction problem.
02:24Here we have the same numbers as before but this time we are subtracting.
02:29We have our blocks set up again with 126 blocks.
02:32This time we need to take away 57 blocks.
02:36As usual we start with our ones place.
02:39We need to take away 7 blocks, 1, 2, 3, 4, 5, 6, wait I can't take away 7 because there
02:49are not 7 ones blocks.
02:51Do you know what I need to do?
02:57What I need to do is trade in one of my tens blocks for ones blocks.
03:02So I take away one of my tens blocks and I get 10 ones blocks from it.
03:10Now I have enough ones blocks to take away the 7.
03:13So we take away 1, 2, 3, 4, 5, 6, 7.
03:20How many ones blocks do I have left?
03:239!
03:25I am left with 9 ones.
03:28Now we move on to the tens.
03:33It says that we have 2 tens but I only see 1.
03:36Do you know what happened?
03:42I remember we traded one of the tens blocks to get 10 ones.
03:47So let's cross out the 2 and put 1.
03:51We now have 1 tens block and we need to take away 5 tens but can we do that?
04:03The only way we can do this is if we trade the hundreds block for tens.
04:08One hundreds block gives us 10 tens blocks.
04:11Can you tell me how many tens blocks we have now?
04:17We have 11 and we need to take away 5 so I remove 1, 2, 3, 4, 5.
04:26Now how many tens am I left with?
04:30I am left with 6 so I put the 6 down here.
04:36If you look at the numbers we have no more hundreds.
04:39Do you remember why?
04:43You are right!
04:44We traded the hundreds for tens so let's cross out the 1 in the hundreds place.
04:51The answer is 69 and we solved it showing all of our work.
04:55Great job guys!
04:57Thanks for all of your help.
04:59We will see you next time.