Three is part of the magic number

My four-year-olds think I’m 20 years old. They counted all the way up there, and then declared that must be how old I am.

Triple grin.

‘Cept they skipped a few numbers along the way, making me closer to 13 or so.

Which I mostly think is cool, but that age puts me back in middle school, and who wants to go back to that?

My second- and third-graders are plowing through big numbers, too, all the way to millions, and they’re not slowing down with the 5-digit addition and subtraction problems I’ve been throwing at them.

Well, okay, can they do 9-digit problems?

Set this up:

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

9 8 7 6 5 4 3 2 1

9 8 7 6 5 4 3 2 1

9 8 7 6 5 4 3 2 1

When your students have all of that neatly written on their papers, tell them to carefully write a 3 under the right-hand column.

Then get to work adding it all up.

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

9 8 7 6 5 4 3 2 1

9 8 7 6 5 4 3 2 1

9 8 7 6 5 4 3 2 1

+                       3

Ooooh…nifty.

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