Do you miss taking math classes in school? Well, then you’re in luck because here’s an ode to the humble calculator! From scientific to pocket calculators, these tiny devices have been making our lives easier since we first learned how to add, subtract, multiply, and divide.
As cool as it would be, tiny elves aren’t inside working out math problems. So how exactly do calculators work? Let’s pull these helpful tools apart, and see what makes them function!
What is a Calculator?
A calculator is a small electronic device that makes mathematical calculations. It’s used by students, financial advisors, accountants, and many others when mental math won’t produce a fast, accurate answer.
Who Invented the Calculator?
The first calculator was invented around 1642 by Blaise Pascal, a French mathematician and philosopher. This groundbreaking device was called the “Pascaline” and came out right in time for the Industrial Revolution when huge changes were occurring in both business and technology.
While the Pascaline was technically the first adding machine to ever exist, the handheld electronic calculator took things to the next level! The most famous is the iconic Texas Instruments (TI) calculator, invented by Jerry Merryman and Jack Kilby in 1967. High school algebra wouldn’t be the same without these groundbreaking gentlemen!
A man named Wilhelm Schikard invented a calculator that came out before the Pascaline. He often doesn’t get credit for inventing calculators, however, because his device had tooth cogs that would often fail. It also couldn’t do subtraction or division!
What Are Calculators Made Of?
Most calculators are made from a durable type of plastic known as acrylonitrile butadiene styrene (ABS). You’ll also find more highend calculators made from stainless steel, aluminum, or brass.
Check out this graphic to see all the different materials used to make calculators!
 ABS Plastic or Metal: Used to make the case
 Soft Plastic or Rubber: Used to make the buttons
 Liquid Crystals: Used to make the screen
 Lithium: Used to make the button cell battery inside of the calculator
Your calculator can last for years thanks to all of these materials. It wouldn’t work quite right if anything was missing from the final design.
What is Inside of a Calculator?
If you pry open a calculator, you will see one giant circuit board inside. This circuit board includes a processor chip, a button cell lithium battery, and sensors that know every time you press down on the buttons.
How Does a Calculator Work?
In simple terms, electrical circuity is what makes a calculator work. As you press down on a button, you trigger a response in a piece of the circuit board known as the “keyboard membrane.” This is essentially the brains of the operation, sending a signal to the processor chip, which in turn, computes the answer and causes it to appear on the LCD screen.
Of course, there’s a little more to it than just that! Here’s a breakdown of how a calculator works:

Step 1 Receives the Input
Each button you press on a calculator is known as an “input.” In the world of electronics, this is a signal for processing on a circuit board. It’s basically a memo to the inside of the calculator that it’s time to wake up and get to work.
Let’s say you’re adding “24 + 58.” The calculator sees that as 5 different inputs: the “2,” the “4,” the “+,” the “5”, and the “8.”

Step 2 Convert to Binary Code
A calculator doesn’t think the way your brain thinks. It processes numbers in binary code, where a combination of “0’s” and “1’s” are used to represent any number.
So in the case of the example above, “2” would become “0010,” “4” would become “0100,” and so on.

Step 3 Combine the Inputs
Now it’s time for the “Logic Gate” to work its magic! This is an electronic component built into the circuit board that combines the inputs together.
“2” and “4” are now “11000” in the binary code, while “5” and 8” are now “111010.”

Step 4 Create the Output
Once you press the “equal” sign on the calculator, you’re sending a signal to the circuit board that it’s time for the output. The calculator is smart enough to know that you want to see the output displayed in integers or decimals rather than in binary code.
In the case of the example equation, you would see “82” on your screen!
You can spend years studying electronics at a trade school, or just consider this your crash course! Isn’t it crazy to think that all of this is happening inside of a device that’s small enough to fit in your backpack or pocket?
How Do You Use a Calculator?
To use a calculator, enter the equation you’re trying to solve. The numbers and mathematical symbols like the plus sign, equal sign, and percentage sign are pretty selfexplanatory, but it takes instruction and practice to get familiar with the rest of the buttons.
This chart breaks down the different buttons on a basic calculator or scientific calculator:
Button  Function 

AC  All clear 
C or CE  Clear 
DEL  Delete or insert an entry 
+  Addition 
–  Subtraction 
÷ or /  Division 
X or *  Multiplication 
=  Equals 
%  Percentage 
+/  Toggle between positive and negative numbers 
() or NEG  Negative number 
( )  Parentheses for equations 
Pi or π  Pi (3.141519) 
√  Square root 
1/X  Fraction 
X^{1}  Inverse of a number 
X^{2}  Square of a number (ex: 5×5) 
X^{3}  Cube of a number (ex: 5x5x5) 
^  Raise to the power of 
X^Y or Y^X  X to the power of y, or vice versa 
E^X or X1  Exponent 
MS or STO  Memory store 
M+/M  Memory add or Memory subtract 
MC  Memory clear 
MR or RCL  Memory recall 
A b/c  Mixed fraction 
LOG or LN  Used for logarithms 
SIN  Sine 
SIN^{1}  Inverse sine 
COS  Cosine 
COS^{1}:  Inverse cosine 
TAN  Tangent 
TAN^{1}  Inverse tangent 
HYP  Hyperbolic functions 
EE, EXP, or 10^N  Exponential values 
RAND  Generates a random number between 0 and 1 
SHIFT  Access different functions 
MODE or DEG  Change the mode for different angles between radians, degrees, and gradian 
ENG  Engineering notation instead of decimals 
This is a general overview, but there could be other mystery buttons on your calculator that you’re not sure how to use. A quick Google search, or a helpful teacher can help you figure out what everything means!
Can Calculators Be Wrong?
Anything is possible, but it’s very, very rare for a calculator to give you the wrong answer. This device is designed for precision, so it’s more likely a user inputting error vs. something going on with the technology.
That isn’t to say all calculators are 100% foolproof. It would just be downright bad math to say otherwise! Check the accuracy of your calculator by performing basic algebraic equations every once in a while, just to make sure it’s working properly.
Can Calculators Run Out of Battery?
If your calculator works via lithium battery, there’s a small chance that it will run out of juice over time. This doesn’t happen often, but it is a possibility if you’re using a cheaply made calculator, or if you accidentally drop or break it.
Do you have a calculator that no longer seems to be working? Try leaving it outside in direct sunlight! Many types of calculators have builtin solar panels that can power the device. You can also try resetting the calculator, or reaching out directly to the manufacturer to see what else you can do about a dead battery.
How Are Calculators So Fast?
Calculators are fast because they work via a microprocessor, which is basically a mini computer. It’s kind of like you making a command or asking your Alexa or Google Home a question and getting a response back within nanoseconds!
While calculators are amazing, you should still be able to do basic math in your head. It just takes practice! Give any of these tips a try to improve your mental math:
Learn the tricks
Find shortcuts to help you do mental math faster. For instance, if you’re multiplying numbers that end in “0,” such as “120 x 40,” you just need to multiply “12 x 4,” and then add the two zeroes at the end (so the answer is “4800.”) There are a ton of tricks like this that you can try, so do your research and stick with the ones that make sense to you.
Memorize
You probably learned your times tables in elementary school, but it’s not a bad idea to memorize other handy building blocks so you don’t have to use a calculator as often. Even something as simple as knowing that 1⁄2 is equivalent to 50% can save you time and effort in the long run.
Calculate the tip at restaurants
It’s always a good plan to tip your waiter or waitress more than the recommended 20%. However, if you want to stick with that percentage, all you need to do is look at the price, move the decimal one place to the left, and then double that amount. So if the bill is $112.00, you should tip at least $22.40.
Do sudoku puzzles
Just like crosswords can improve your vocabulary, sudoku puzzles can improve your mental math. Do a puzzle or two while you’re watching Netflix in the evening, or when you’re waiting in line at the grocery store.
Take a class
Maybe you already graduated from high school or college, but that doesn’t mean you still can’t take math classes as an adult. Enroll in a class at a community college if you feel like your math skills are lacking.
Find any excuse you can to practice your math, even if it means keeping your calculator in your bag or drawer. It’s worth keeping your brain sharp and not relying too much on technology!
Why is the Calculator Important?
The human brain is wonderful, but it’s only able to handle so much. Calculators are there to take care of the rest! Some truly remarkable achievements wouldn’t be possible without them.
NASA couldn’t go on missions in space, the railroads would have taken longer to build, and many of us wouldn’t have made it out of 6th grade without calculators. They may be small, but these tools are important because they keep our math accurate and help us make calculations at a faster rate.
Stats for Success
The market for calculators is worth over $300 million.
An estimated 80% of the calculators purchased by consumers are made by Texas Instruments (TI). These graphing calculators are primarily used by middle and high school students.
33% of people think they’re good at math, but score on the bottom half of tests.
The Bottom Line
No one is going to think you’re bad at math just because you pick up a calculator. Whether you’re trying to graduate high school, building a new home, or creating a budget for your finances, it helps to have a reliable calculator by your side!
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