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Picture of How To Make A Working Mechanical Lego Calculator
This Instructable will show you how to make a functioning lego calculator that can add +,subtract -,multiply x, and divide \! It uses a gear train that turns one rotation of the control knob into a tenth of a rotation on the tens dial. By engaging, rotating to numbers, and disengaging the control knob in patterns you can do basic arithmetic. Thank you and enjoy!!

Step 1: Make Base And Frame

Picture of Make Base And Frame
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14, 9:39 PM.jpg
You can place the two supports anywhere on the base as long as you keep the supports two studs apart. It depends on how tall your paper indicator is.
 
just for rate7 months ago

nice

dragonslayer59 months ago
Its awesome ,i messed up :( i fixed it though
patelshanim12 months ago

nice..could anyone tell me where should i get(buy) all the lego parts??

thank

aschmidt131 year ago

I liked it, for real, but I see you made a mistake.

dividing is NOT subtracting the same number over and over again.

bobwojo aschmidt1312 months ago

Actually it is, You count how many times you can subtract a from b.

http://www.homeschoolmath.net/teaching/md/division-repeated-subtraction.php

aschmidt13 bobwojo12 months ago

mm, I just thought he meant the actual result of some substraction was the division... which made no sense.

bobwojo aschmidt1312 months ago

For sure his explanation is not complete for both multiplication and division.

dividing is counting how may times it takes to subtract a dividend by the divisor, so yeah it is subtracting by the same number over and over again, why do you think in long division you subtract and come to the same answer that a calculator would

makerx21 year ago
Thanks, Qtechknow!
makerx21 year ago
All of you, THANK YOU SOOO MUCH!
Qtechknow1 year ago

Nice job!!!

I'm going to round up the kiddos and try this right now!

PatJones1 year ago

Ha! Brilliant!

tedrich1 year ago

Excellent work!! Curt Herzstark would have been proud. Check out this video of how his Curta calculator works. https://www.youtube.com/watch?v=loI1Kwed8Pk

Exocetid1 year ago

Ingenious! Babbage would be proud. I teach a course in Digital Logic Design from time to time and in the introductory lecture I touch on the history of computation, which features an adding machine. I plan to build one of these and use it as a demonstrator--great job!

what a great idea, great job

Arman55921 year ago
Awesome ! I had a little mechanical calculator but it could just multiply !
Verticees1 year ago

This is amazing, I've never seen anything like this before!