I'd multiply by 10 first. Saves having any fractions in the mix.
-
-
-
I ask the 8 yo about this, and he said he tried it this way first, but that 5 yo could only halve small numbers.
-
Well, good work then

End of conversation
New conversation -
-
-
Check out https://en.m.wikipedia.org/wiki/Trachtenberg_system … if you want to teach them awesome mental math
-
I own the book about it actually.
-
Leave it somewhere findable for enquiring minds
End of conversation
New conversation -
-
-
So fun to have kids learn that the "8s" are 8,6,4,2,0 repeat -- forever. And other neat hacks like "9s" always add up to 9.
- 1 more reply
New conversation -
-
-
Nice.. You should talk to my buddy, who changed my family's life
@DLouzonishttps://www.linkedin.com/pulse/hey-entrepreneurs-10x-your-kids-too-daniel-louzonis …Thanks. Twitter will use this to make your timeline better. UndoUndo
-
-
-
A strong recommendation for you: Steven B Smith's THE GREAT MENTAL CALCULATORS. Surprisingly illuminating stuff. http://amzn.to/2y6g1ee
-
An interesting minor tidbit for you: several of the most powerful mental calculators known to history were illiterate.
- 1 more reply
New conversation -
-
-
I would have reversed those steps in order to avoid fractions. Of course, that could result in integer overflow instead...
- 1 more reply
New conversation -
-
-
I enjoy your essays. Thanks for sharing.
Thanks. Twitter will use this to make your timeline better. UndoUndo
-
-
-
My 3rd grade teacher gave times tables as
#punishment forget I will not talk. Would never work. But I can multiply and divide like a
Thanks. Twitter will use this to make your timeline better. UndoUndo
-
-
-
It works similarly but less well in my house; the 5 year old tries to teach the 3 year old how to add numbers. I guess I need to wait a bit.
Thanks. Twitter will use this to make your timeline better. UndoUndo
-
-
-
Thanks. Twitter will use this to make your timeline better. UndoUndo
-
Loading seems to be taking a while.
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.