Napier's Promptuary

Napier developed his Promptuary to solve a problem with his bones.

Have a look at the short introduction video.

Napier's Promptuary Video

Using his bones to multiply your number by another number with more than one digit meant that you needed to write lines of part answers before adding to get your final answer.

Try a Promptuary example.

Napier's Promptuary Examples

Napier wanted his Promptuarys made to multiply numbers with up to 10 digits by numbers that also had up to 10 digit giving answers with up to 20 digits!

Spikes version here is only 5 by 5 and only 25 cards and 25 covers, both half length.  A great saving, but you can still multiply 10 by 10's with very little extra calculation.

This needed number strips and covers with 60 accurate triangles on them. 100 cards and 100 covers are needed to allow every number to be used.

Try building a Promptuary. This needs to be done accurately.

Build a Promptuary

Napier's Promptuary

Have a look at the short introduction video.

Napier developed his Promptuary to solve a problem with his bones.

Using his bones to multiply your number by another number with more than one digit meant that you needed to write lines of part answers before adding to get your final answer.

Try a Promptuary example.

Napier wanted his Promptuarys made to multiply numbers with up to 10 digits by numbers that also had up to 10 digit giving answers with up to 20 digits!

Spikes version here is only 5 by 5 and only 25 cards and 25 covers, both half length.  A great saving, but you can still multiply 10 by 10's with very little extra calculation.

This needed number strips and covers with 60 accurate triangles on them. 100 cards and 100 covers are needed to allow every number to be used.

Try building a Promptuary. This needs to be done accurately.

Napier's Promptuary

Napier developed his Promptuary to solve a problem with his bones.

Have a look at the short introduction video.

Using his bones to multiply your number by another number with more than one digit meant that you needed to write lines of part answers before adding to get your final answer.

Try a Promptuary example.

Napier wanted his Promptuarys made to multiply numbers with up to 10 digits by numbers that also had up to 10 digit giving answers with up to 20 digits!

This needed number strips and covers with 60 accurate triangles on them. 100 cards and 100 covers are needed to allow every number to be used.

Spikes version here is only 5 by 5 and only 25 cards and 25 covers, both half length.  A great saving, but you can still multiply 10 by 10's with very little extra calculation.

Try building a Promptuary. This needs to be done accurately.

Napier Maths