Sumat 6
Introduction
The Addimult Sumat 6 is a mathmatical aid designed to aid the user in addition and subtraction calculations. Addimult was primarily based in Germany and Liechtenstein, which produced mechanical slides of allowing the user to add and subtract numbers of different amounts of digits (usually from 5 to 9). Addimult produced sliders from the 1930s to the 1960s.
This summer, I found and purchased a Sumat 6 in antique shop in Manhattan Beach, California. It was fortunate that the Sumat 6 came with a nice pouch, which was still intact and instructions. It is a very classy machine which held up well for at least a 50 year old machine.
The Sumat 6 presented today has a six digit capacity. The slider is made of metal and has two sides:
The Addition Side (slider bar on top)
The Subtraction Side (slider bar on the bottom)
The Sumat 6, like all the mechanical slides produced at the time, has a metal stylus. The stylus is used to push columns up and down in holes. On top of each column has a circle that shows its value. The markers in each column are either metallic silver or painted red. For example, on the Addition side, a column that shows three red markers followed by seven silver markers gives the column a value of 3. On the Subtraction side, a column that shows seven red markers followed by three silver markers shows a value of 3.
Addition and Subtraction
The value changes depending on what direction you push the slide:
| Operation |
Slide Down |
Slide Up |
| Addition |
value increases |
value decreases |
| Subtraction |
value decreases |
value increases |
There are two additional markers, shown in red: the up arrow and the down arrow.
Red Up Arrow ( ↑ ) : Push the next left column down 1. Scroll the current column all the way up (0 on the Addition side, 9 on the Subtraction side)
Red Down Arrow ( ↓ ) : Push the column down one spot (to 0 on the Addition side, 9 on the Subtraction side)
Updating one column does not automatically update other columns, so you need to keep your addition and subtraction processes in your head as you are calculating.
Examples
Example 1: 425 + 784
Use the Addition side. Set the sliders to 000425.
Start with the ones digit, which in this case is the right-most column. Slide it down four notches. So far, so good. Readout should have 000429.
Now the tens, slide the column down 8. Note that after 8 notches we hit the red up arrow. Slide the hundred column down 1 and reset the tens column to 0. You are done in the tens column since 8 notches are slid. Readout should have 000509.
Finally the hundreds column, slide it down 7 notches. Note after 5 notches, we hit the red up arrow again. Time to slide the thousands column down 1 and reset the the hundreds column to 0. We need to slide the hundreds column 2 more notches (5 of the 7 have been used). The readout now has 001209.
The answer: 425 + 784 = 1209
Example 2: 1365 - 746
Use the Subtraction side. Set the sliders to 001365.
In this problem the right-most column represent the ones digit.
Start with the ones digit and slide it down 6. Note after six notches until the red up arrow is reached. Slide the tens column down 1 and reset the ones column to 9. Readout now should read 001359.
Now slide the tens column down 4. Readout: 001319.
Now the hundreds, slide it down seven notches. After four notches, the red up arrow is reached. Slide down the thousands column and reset the hundreds column to 9. We have three notches left, so slide the hundreds column down 3. Readout: 000619.
We are done.
The answer: 1365 - 746 = 619
Sources
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Eddie
All original content copyright, © 2011-2020. Edward Shore. Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited. This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author.
