Math Strategy-Napier’s Bones for Long Multiplication

So, who is Napier and why are we talking about his bones?

If you want to dive deep into the world of John Napier, feel free to lose yourself in historical bliss. However, if you are like me and want the facts, keep reading. It took me several tries for my brain to soak in it’s goodness, but once it did, oh wow! Long multiplication became trivial allowing us to move on to better things in life, like more math!

I’ve included videos below which explains the method. Take it slow. Watch them fully first then let the information soak in. Don’t worry if you get lost initially, we sure did. However, once we learned this method long multiplication was tamed and no number was too large to induce panic.

For our homeschool, we started by learning how to draw the grid. Consider it an art project. Yes, it it art! Decorate if necessary. Use different colors. Justify purchase of more gel pens!!

Once you have mastered the grid, congratulate yourself and focus upon the numbers. There are two main ideas. Learning how to place the numbers in the grid and learning how to add the numbers across the grid. Don’t try to tackle it all at once, slowly ease into it. You’ll also carry numbers, but take it slow and it will also start to come easy.

It might take a few tries (it did for us), but after a few moments of questioning sanity…

…it happened…

…a miracle…

Endless numbers by endless numbers could be multiplied with ease. Toss us a 45,098 times 34,921 and several pen strokes later an answer will emerge victoriously. Even if distractions lure your mind away, this technique makes if easy to find where you left off so you can continue.

It’s now our go-to method for multiplying large numbers. The beauty is that pieces of it allowed us to foil the F.O.I.L. method.

Technically, you can make your own manipulatives out of sheets of paper; however, we ditched paper in lieu of the drawings and used our mental math facts. The below video showcases the more hands on approach. Every student learns differently, so do what works for your child.