What a scientific calculator does and when you need one
A scientific calculator performs the same addition, subtraction, multiplication, and division as a basic calculator, but it also handles functions that show up in algebra, geometry, trigonometry, and physics. If you need to find a square root, calculate a percentage, work with angles, or use exponents, a scientific calculator is the tool for the job. Most smartphones have a scientific calculator built in — on iPhone, open the Calculator app and turn your phone sideways to landscape mode; on Android, open Calculator and tap the menu icon to switch to scientific view.
The difference between a basic and scientific calculator is the buttons. A basic calculator has the four operations and a few memory buttons. A scientific calculator adds rows of function buttons for powers, roots, trigonometry, logarithms, and constants. Learning where these buttons are and what order to press them in is the only barrier to using one.
Key Takeaways
- Enter the number first, then press the function button — the calculator processes the operation when you press equals or the next operation button.
- The ^ or x^y button raises a number to a power; the √ button finds the square root of the number you entered.
- Trigonometry buttons (sin, cos, tan) work in degrees or radians depending on the mode you select — check the display to see which one is active.
- Parentheses buttons let you group operations so the calculator solves them in the right order, which matters when you have multiple steps.
- The memory buttons (M+, M−, MR) store a number so you can recall it later without retyping it.
The basic layout: where the main buttons are
The number pad and basic operations (+ − × ÷) sit in the same place on every calculator. The scientific functions surround them. On the left side, you will usually see a column of buttons for powers and roots: x² (square), x³ (cube), √ (square root), and ^ or x^y (any power). Above or below these sit the trigonometry buttons: sin, cos, tan. On the right side are memory buttons: M+ (add to memory), M− (subtract from memory), MR (recall memory), and MC (clear memory).
At the top, you will find buttons for parentheses ( and ), a button labeled DEG or RAD to switch between degrees and radians, and often a button for π (pi). The = button sits where you expect it, usually on the right side near the bottom. Some calculators have a C button to clear the current entry and an AC button to clear everything.
How to enter and solve a basic operation
The order is always: number, operation, number, equals. Press 5, then +, then 3, then =, and the display shows 8. This works the same on a scientific calculator as on any other. The difference comes when you chain operations together or use functions.
If you enter 5 + 3 × 2, the calculator follows the standard order of operations (multiply before adding) and gives you 11, not 16. This is one advantage of a scientific calculator — it knows the rules of math, so you do not have to work around them. If you want to add first, use parentheses: (5 + 3) × 2 gives 16. Enter the opening parenthesis, then 5, then +, then 3, then the closing parenthesis, then ×, then 2, then =.
Using powers, roots, and exponents
To square a number, enter the number and press x². Type 7 and press x², and the display shows 49. To cube a number, enter it and press x³. For any other power, use the ^ or x^y button: enter the base number, press ^, enter the exponent, then press =. To calculate 2 to the 5th power, press 2, ^, 5, =, and you get 32.
To find a square root, enter the number and press √. Type 16 and press √, and the display shows 4. Some calculators require you to press √ first and then enter the number — check your manual or try both ways. For roots other than square roots (like cube root), look for a button labeled ⁿ√ or x^(1/y). The process is the same: enter the number, press the button, enter the root value, then press =.
Working with trigonometry and angles
The sin, cos, and tan buttons calculate the sine, cosine, and tangent of an angle. Before you use them, check whether your calculator is in degree mode or radian mode — look at the top of the display for DEG or RAD. Most everyday problems use degrees. If you see RAD and you need degrees, press the mode button (often labeled MODE or DRG) until DEG appears.
To find the sine of 30 degrees, make sure you are in degree mode, then enter 30 and press sin. The display shows 0.5. The order matters: number first, then function. If you press sin first, the calculator will not know what angle you want. For inverse functions — finding the angle when you know the sine — look for buttons labeled sin⁻¹, cos⁻¹, or tan⁻¹, or press a SHIFT or 2ND button to access them.
Using memory to store and recall numbers
Memory buttons let you save a number so you can use it later without retyping. Press M+ to add the current display to memory, M− to subtract it from memory, and MR to recall what is stored. Press MC to clear the memory and start fresh. This is useful when you are solving a multi-step problem and need to keep an intermediate result.
For example, if you calculate 15 × 8 and get 120, you can press M+ to store it. Then calculate 25 × 6 to get 150, and press M+ again to add it to memory (now memory holds 270). When you press MR, the display shows 270. Some calculators show an M indicator on the display when memory is not empty, so you know there is a stored value.
Common mistakes and how to fix them
The most common mistake is pressing the function button before entering the number. If you press √ first and then 16, the calculator may show an error or give you the wrong answer. Always enter the number first. The second mistake is forgetting to switch between degree and radian mode. If you calculate sin(30) and get 0.5, you are in degree mode. If you get −0.988, you are in radian mode and need to switch.
A third mistake is forgetting to close parentheses. If you enter (5 + 3 without pressing the closing parenthesis button, the calculator may give an error or wait for you to finish. Count your opening and closing parentheses to make sure they match. Finally, if the display shows a very long decimal (like 0.33333333), the calculator is showing you the full precision of the answer. This is correct — round it yourself if you need fewer decimal places.
Frequently Asked Questions
What is the difference between DEG and RAD mode?
Degrees and radians are two ways to measure angles. A full circle is 360 degrees or 2π radians. Most everyday math uses degrees, so keep your calculator in DEG mode unless you are studying advanced trigonometry or physics. If your trigonometry answers look wrong (very large or very small), you are probably in the wrong mode.
Why does my calculator show a very long decimal instead of a simple answer?
Scientific calculators show the full precision of the answer. If you divide 1 by 3, the true answer is 0.333... repeating forever, so the calculator shows as many 3s as it can fit. This is correct. Round the answer yourself to the number of decimal places you need, or look for a rounding button on your calculator.
How do I calculate a percentage on a scientific calculator?
Most scientific calculators have a % button. To find 20% of 50, enter 50, press ×, enter 20, press %, then press =. The answer is 10. Some calculators require you to press = after the % button, and some do not — try both ways if the first does not work.
Can I use a scientific calculator on a test?
That depends on the test. Some tests allow scientific calculators, some allow only basic calculators, and some do not allow any calculator. Check your test rules before the day of the test. If a scientific calculator is not allowed, you will need to know how to do the math by hand or use a basic calculator instead.
What does the E or EE button do?
The E or EE button enters a number in scientific notation, used for very large or very small numbers. Pressing 5, E, 3 enters 5 × 10³, or 5000. This button is rarely needed for everyday math but appears on scientific calculators because they are designed for science and engineering work.