Introduction: Hacked Calculator Prank

Picture of Hacked Calculator Prank
Hack a calculator to make crazy sounds or say wacky things just for fun.

Step 1: What You Need...

Picture of What You Need...

1. A calculator
2. A device that uses a recording module. In my case I found a cheap automotive memo thingy that sticks to the windshield and allows you to record up to 5 different messages and play them all back. You could use a regular single sound module like one from Radio Shack.

NOTE: You will have to find a calculator that is thick eoungh to hold the module inside it's case.

Step 2: Prepare the Recording Module

Picture of Prepare the Recording Module

Before you do anything else, record what you want the calculator to "say" on the module. I actually ran a jumper from the microphone input to a mini plug that plugged into my audio card on my PC and then I recorded some .wav sound effects.

Then disassemble the device to get to the recording module. You can clip the microphone connections or leave them depending on how much room you have inside the calculator.

Step 3: Prepare the Calculator

Picture of Prepare the Calculator

Take apart the calculator and decide what key you want the sounds to play from. I chose the EQUAL sign key because that always has to be pressed. You could choose a number key that would play the sounds only when that number was pressed or the minus key...your choice.

Step 4: Make Your Connections

Picture of Make Your Connections

Run two small wires from each side of the contact on the calculator key you decide to use. Then run those two wires to the playback contacts on the module. Run the two power wires from the module to the positive and negative ends of the calculator battery terminal. When the calculator key is pressed, it will complete the circuit for that key and also the playback button.

Step 5: Close It Up

Picture of Close It Up

Close up the calculator and make sure no wires are sticking out. Re-insert the battery and your calculator prank is ready to use! Each time the "=" sign is pressed, the module will playback the 5 recorded sounds and then repeat. Have fun!


Emsaid (author)2011-06-15

just made one of these, but i used a circuit from a toy duck...I was able to fit everything in without any bulges just fine, it was awesome! I put it in one of the calculators you can borrow at my school right before the final exam, haha the teacher handed it to one of my friends and she turned it on and it started quacking and wouldnt stop! today the teacher was talking about it "somebody wired a speaker in there! very clever" she still doesnt know it was me haha Great hack!!

WHITEREVELATOR (author)Emsaid2016-12-05

Sounds Hilarious

modaawesome (author)Emsaid2011-12-11

its a quackulator

nuthara (author)2015-04-28

its great!

chalky (author)2009-01-02

this would be cool if you adapted it to fit inside the TV remote lol:)

Hoboman (author)chalky2009-01-08

Think this is big enough?

singerboy41 (author)Hoboman2015-03-30

(gasps) We have that remote at our house! I wish it worked, though... I would totally use it all the time!

churchman (author)Hoboman2010-09-07

no it needes to be way bigger

dsman195276 (author)Hoboman2009-07-11

i had one, but i lost it...

sharlston (author)Hoboman2009-05-17

im a proud owner of one

prestonm (author)sharlston2009-05-26

me too

dombeef (author)Hoboman2009-05-01

I used to own one!But it broke :-(!!!

Mr. Squishy (author)Hoboman2009-03-17

I found one of those giant remotes at Canadian Tire!

struckbyanarrow (author)Hoboman2009-03-12

thats a television remote silly

awang8 (author)chalky2009-01-02

Hmm... I might work on that.

coolsista9 (author)2014-03-20


Taost (author)2010-04-03

Now all you need is a hack that makes any answer "666". That's so gonna make your friend freak out!

sonofspikerr (author)Taost2011-02-15

lol thats awesome

mariomaster856 (author)2010-12-22

HA HA HA HA! loveit!

Squid Tamer (author)2009-01-02

Genius! I wonder what else fits inside a calculator?

geeklord (author)Squid Tamer2009-01-02

C4, I mean nothing, nothing at all....... :D

bowmaster (author)geeklord2009-01-02

The problem is C4 is a high explosive which need detonators. I guess if it was a graphing calculater you could fit a detonator inside.

Sandisk1duo (author)bowmaster2009-01-02

You can detonate C4 by lighting it on fire, then smashing it (or just stomping it)!

PKTraceur (author)Sandisk1duo2009-01-03

Actually, fire and sudden impact has slight to no effect on C4. C4 stands for Class 4 Explosive. The only way to "detonate" it sufficiently to go "boom" is to run an electrical charge through it. Sorry to be the buzzkill, but just I just like to share my knowledge. (Wikipedia it, they have some interesting articles!)

Sandisk1duo (author)PKTraceur2009-01-03

wait, i just read [ wiki]

Because C-4 burns slowly when it is ignited with a flame rather than detonated with a primary explosive, soldiers during the Vietnam War era would sometimes use small amounts of C-4 as fuel for heating rations while on long patrols. While many soldiers used C-4 safely in this manner, there are several anecdotes about soldiers attempting to put out the fire by stomping on it — causing it to detonate.

not to be mean or anything but, did you miss that part?

PKTraceur (author)Sandisk1duo2009-01-03

Must've forgotten. Well, still, an electrical charge is necessary for a timely and "neat" detonation.

geeklord (author)PKTraceur2009-01-03

any idea how much charge is needed?

Sandisk1duo (author)geeklord2009-01-03

hmm.... you could have a coil of wire ignite the C4, then you'll need to apply pressure, maybe have a 9mm round hit the burning C4

Kipkay (author)Sandisk1duo2009-01-03

Wow have the comments gone off "target"

PKTraceur (author)Kipkay2009-01-03

Sorry for junking up your 'ible Kipkay. Probobly my fault.

Kipkay (author)PKTraceur2009-01-03

No biggie..I just thought it was funny that this turned into some kind of bomb prank. Believe me...I had much crazier ideas about how this one could go 'boom'

geeklord (author)Kipkay2009-01-04

If this makes any sense, What is the explosive(non-nuclear) with the best size to blast ratio?

kacper00100 (author)geeklord2009-01-09

I think its francium but its really really rare (second rarest element in the world)

geeklord (author)kacper001002009-01-12


jimmytvf (author)geeklord2010-09-09

would be nice too, with a high voltage charge, ignite a small firework and blow it off :P

chalky (author)Kipkay2009-01-03

you mean "worryingly" off target Kip lol

Sandisk1duo (author)Kipkay2009-01-03

people ask questions, they get answers

bowmaster (author)PKTraceur2009-01-03

I think a calculator full of flash powder would cause a big enough explosion.

Sandisk1duo (author)bowmaster2009-01-03

no, i doubt it, you need to apply heat and pressure for it to detonate

PKTraceur (author)Sandisk1duo2009-01-03

Again, not neccasarily, perhaps put Compsition C-4 between the equal button-pad and the PCB, so an electrical charge goes through? This is all theorized, so I have NOT done it.(I hope the millitary does'nt crack down on this...)

Sandisk1duo (author)PKTraceur2009-01-03

well that wouldn't do any good, you'd be putting 3v through the C4, wouldn't combust either light it on fire and smash it with a hammer, or use a detonator All of this information is on the internet, from sources such as Wikipedia and how stuff works

xproplayer (author)Sandisk1duo2009-01-04

use a micro transformer from a digital camera (yes they do have super slim versions i know ive taken apart every disposable camera known to man) and put 300v through it lol

Sandisk1duo (author)xproplayer2009-01-04

hmmm.... forget about the transformer just use the 300v 120uf capacitor but that's not how the detonator works... there is probably some chemical that detonates the C4

Smurfy12.9 (author)PKTraceur2009-01-09

um excuse me it stands for composition 4 like comp D from WWII but lighting it on fire will make it burn my father when with the military in alaska his platoon would make almost like a candle and light the tip and it burns forever almost stomp on it even if its not lit will most likely make you lose a foot because the electrical charge actually causes the plastic to constrict and explode

peanut butter...:P sorry, felt like saying that

Maybe you could make a folding panzerschreck to come out?


PKTraceur (author)Millawi Legend2009-01-03


churchman (author)2010-09-07

What a wacko lol man people think of the funnyest things!

memyselfand1 (author)2009-01-25

It does look a little fake; in the video at the end, the calculator body moves when you press the button. The board doesn't fit in with the other board and kind of gives the game away. Sorry, good idea otherwise.

About This Instructable




Bio: Tinkerer, hackster and prankster. Hit me up on Facebook: Thanks for checking out my Instructables!
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