Please teach grade 1 students addition within 20 with regrouping, such as 7+8
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Hello, first graders! Today we're going to learn how to add numbers like 7 plus 8. Sometimes when we add, the answer is bigger than 10, and we need to do something special called "regrouping" or "making a ten." It's like making a friendly group of 10 first because adding to 10 is super easy! Let's look at 7 plus 8 together.
Now let's look at our numbers 7 and 8. Which number is closer to 10? It's 7! The number 7 only needs 3 more to become 10. Let's count together: 7, 8, 9, 10. So 7 plus 3 equals 10. We need to find 3 more to help the 7 become a nice group of 10.
Now we need to break apart the 8! We need 3 from the 8 to help the 7 make 10. So let's split the 8 into two groups: a group of 3 and a group of 5. Watch as we separate the 8 dots. Three dots will help the 7, and 5 dots will be left over. So 8 equals 3 plus 5.
Now let's give the 3 to the 7! Watch as the 3 yellow dots join the 7 blue dots. 7 plus 3 equals 10! We made a beautiful group of 10! Now we have 10 plus the leftover 5. Making a ten first makes our addition much easier. We turned our hard problem into an easy one: 10 plus 5.
Now we just add 10 plus 5! What is 10 plus 5? It's 15! So 7 plus 8 equals 15! We did it! We used the special trick called "making a ten" to solve our problem. Instead of adding 7 plus 8 directly, we broke it into easier steps: we made 10 first, then added the leftover 5. Great job learning this new strategy!