I first encountered Napier's Bones back in Mrs. Hutnick's 4th grade EL math class. We had a 'build day' of sorts in which we made our own Napier's Bones, and at the time I thought they were really cool. Now, a bunch of years later, I still think they're really cool--they're very simple to make and to use, they are durable, and they can be personalized in any way you see fit.

My old pair is quite sloppy (though not bad for a 10-year-old, I'd say. Good job, former me), so I decided to make a new and improved set--documented here on Instructables.

Now for the important part: what Napier's Bones are. They are a multiplication tool/math toy that allows you to multiply 0-9 with large numbers extremely quickly with only slabs of wood. As long as you add small numbers and read correctly, you will get the correct solution every time.

My old pair is quite sloppy (though not bad for a 10-year-old, I'd say. Good job, former me), so I decided to make a new and improved set--documented here on Instructables.

Now for the important part: what Napier's Bones are. They are a multiplication tool/math toy that allows you to multiply 0-9 with large numbers extremely quickly with only slabs of wood. As long as you add small numbers and read correctly, you will get the correct solution every time.

Watch the video below while relaxing to the smooth tunes in the background:

This is actually how I learned long multiplication ( using lattice multiplication, not this toy ). I wish I had thought of this when I was teaching it to my daughter. Would have been a great way to illustrate. <br> <br>That said, I also initially failed a math test in high school because my trig teacher couldn't "read my work" and told me she didn't believe that my lattices were actually math. <br> <br>Then I had to teach the class how to do lattice multiplication before she'd correct the grade.

I love this kind of stuff , Thank you, now am off to the shop to build my own

I actually made it into foam board.

can you multiply more digits?

if you make more bones, you can multiply more digits.

thanks for the fast answear

This is great. I love playing with numbers (and I work with them a fair bit). This really wet my appetite, so I looked up some more info:<br/> <a rel="nofollow" href="http://en.wikipedia.org/wiki/Napier%27s_bones">http://en.wikipedia.org/wiki/Napier%27s_bones</a><br/><br/>It adds to your explanation, and tells of more things we can do with it, making your Instrucatable even more valuable!<br/>

very helpful

this pic might help:http://pages.cpsc.ucalgary.ca/~williams/History_web_site/Graphics/Napiers%20bones%20etc/napiers%20bones.gif<br/>

Very well put together.....I just need to learn how to use them!!
Probably easier than I thinkt....but i'm thick!!
Thanks.

as noted below, wikipedia explains.

Sometimes I'll draw a "Napier's grid" to do multiplication instead of trying to line-up all of the columns vertically. The first time I did this, I got weird looks from some friends, but I was doing (6 figure * 6 figure) multiplications faster than the rest of them.<br/>

Muito legal!!!
Muito mais fácil de usar que o ábaco!
Congratulações!

I love this! I'm thinking of building a couple of sets for my puzzle loving nephews. They should get a kick out of it. OK. It isn't a puzzle, I realize that, but because they like puzzles, we have the material because we keep making stuff for them. I am thinking though, that it would be great if the wood could be finished.

Mrs. Hutnick? Nice.
By the time they let me in her EL math class, it was the end of fifth grade and we were playing with platonic solids.

I love that :)
Will do as soon i find the wood ;)

my new fevered Instructable

holly fucking awsomnes

I had to watch the video twice, but I get it. This is a really neat project!

And I like your instructions. They are really thorough!

this is the method that was taught when my dad was in school. i don't recall him saying anything about using a tool like this, but the thought process was the same.
it's disgusting how he can spout off a number before i can even get it written down.

Neat way to do math.

I think i get it, ill have to make it and test it out :P
Very nice way to work math out though :
5 *

I'm really happy you posted this. I now understand how to use them! I was at a bit of loss while you were working on them. :P