Napiers Bones

£13.99
Tax included.

John Napier (1550-1617), discoverer of logarithms, designed this popular calculating tool known as Napier's cylindrical 'rods' or 'bones'. This calculating device allowed the user to carry out multiplication and division. 

The 'bones' consist of a set of rectangular rods, each marked with a counting number at the top, and the multiples of that number down their lengths. When aligned against the row of multiples, any multiple of the top number can be read off from right to left by adding the digits in each parallelogram in the appropriate row. Multiplication is thus reduced to addition and the bones can also be used for division and to calculate square roots. 

A detailed instruction booklet is included. 

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Shipping

We aim to ship orders within 48 hours. 
For UK deliveries, we use DHL Parcel (UK) and EVRI. 
For deliveries to Europe we offer a choice of DPD or DHL.
For deliveries outside Europe, we ship by DHL.

Our warehouse works Monday to Friday only. If we receive your order by 10am then we aim to ship the same day or the next day, depending on how busy the warehouse is. On the day your order ships, the warehouse will send you your tracking number by e-mail at 7pm UK time. The delivery time to reach you will depend on the shipping option you have chosen. 
Returns

We will accept items that you wish to return, within 30 days of placing the order. You are responsible for the cost of shipping the item back to us, and it must be in saleable condition. We will refund you the cost of the item. Please let us know if you wish to return an item before you send it. 

If the item is faulty, please let us know, and we will ship a replacement or refund your money, as you wish.
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Customer Reviews

Based on 26 reviews
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MR SIMON PASS
Fantastic Object - Love it.

Fantastic object. I've got young kids and trying to get them into maths and patterns and this is perfect.

S
Samantha O.
Napiers Bones

So excited to have found these for my husband.

P
Piotr Z.
Napiers Bones

The Napiers bones are superb, my students like them very much. Yours, Piotr.

M
Mark Wilson

Napiers Bones

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Sarah Ball

Napiers Bones

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