Long Addition/Subtraction/Multiplication

To help you do long addition, subtraction, multiplication (and even division) when you don't want to or can't use a pen & paper e.g. in the rain.
Can be used to do latitude/longitude/time calculations with the Hangdial, StarSquare, and StarRings.

Better than an abacus- nothing to accidentally slide on you, and I keep forgetting where I'm up to with an abacus when doing carries and end up making mistakes: but not with this! Could also be used as a teacher aid.

There are TWO designs- one for long addition and subtraction only (it has a '10+' carry/borrow plate); and one which also supports multiplication (it has +10 up to +90 carry plates, and all plates are a little thicker too and all text more raised for no particular reason).

Both designs include a '10' digit plate, which is sometimes a convenience- but if you don't like it you don't have to use it of course.

For decimal places, just use remember that the last digit or last two digits or whatever are after a decimal point, in ea