Pile ’Em Up and Stretch ’Em Out: Adding and Subtracting Two-Digit Numbers in Expanded Form

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We’ve talked about a few ways to do problems like 23 + 51. But now let’s see how the kitties do it! Have you ever seen kittens snuggling, stretched out and lying on top of each other? It’s so cute.

 
That’s terrifying.

Well, numbers pile up and stretch out, too! Let’s make a kitty pile with 23 + 51 and stack them:

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Now we’ll stretch ’em out and add ’em up!

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See? We can circle the numbers in the ones place together and add those up (3 + 1 = 4), and then do the same thing for the tens place (20 + 50 = 70). Then we just add 70 + 4 = 74. And now we’ve shown that 23 + 51 = 74. Nice job!