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# Regrouping in addition: 10 tens is regrouped as one hundred (2nd grade math)

First I show with a visual model how, in adding two 3-digit numbers, we may get more than 10 tens, and those are then regrouped with the hundreds (we get an extra hundred). I soon tie the visual model in with the usual way of writing one number under the other.

Later in the lesson I also show what happens when we add 3 numbers, and the sum of the tens exceeds 20.

We also look at just a few mental math problems: 80 + 70, and how we can use that result to also solve 280 + 70 and 580 + 70.

Lastly there is a PUZZLE to solve, once again, which makes Mathy so happy!

If you cannot see the video above, click here for an alternative video player.

Regrouping twice in addition (3 digit numbers)

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