A scientific calculator looks like it has too many buttons the first time you pick one up. It does not. Every key belongs to one of four layers: white number and operator keys, a yellow SHIFT layer, a red ALPHA layer, and a MODE key that changes what the calculator does. This guide on how to use a scientific calculator walks the keypad in the order you will meet it, with one worked example after each new key so you can check your presses against ours.
On this page
- The short version
- 1. Read the keypad
- 2. Follow the order of operations
- 3. Negative numbers: (-) versus the minus key
- 4. Fractions and the S⇔D key
- 5. Powers and roots
- 6. Trig and the angle unit
- 7. Logs: log, ln and log base a
- 8. Scientific notation
- 9. Ans and memory
- 10. DEL versus AC
- Common beginner mistakes
- FAQ
How to use a scientific calculator: the short version
Pick a MODE for your problem, then type the expression with the white number and operator keys. SHIFT reaches the yellow function above a key, ALPHA reaches the red one, and equals solves it, closing any open bracket. DEL removes one character, AC clears everything, and Ans, STO and RCL carry a result forward.
Think of this as scientific calculator buttons explained one key at a time, with the exact labels you will see on the keypad and a live link so you can run every example yourself.
1. Read the keypad
Look at the keypad first. The bottom two thirds are white number keys, 0 to 9 and the decimal point, and the four operators plus, minus, multiply and divide, ending in the big = key. Above the number pad sits a block of specialist keys, including RCL, the brackets, S⇔D and M+, for memory and grouping.
Two keys change what every other key does. SHIFT is gold and unlocks the small yellow label above a key: press SHIFT then x² and you get x³, since "x³" is the yellow label above the x² key. ALPHA is red and does the same job for the red labels, mostly the letters A to F plus X, Y and M, used for stored variables. MODE opens the list of the calculator's 8 modes.
| Mode | What it is for |
|---|---|
| COMP | Everyday arithmetic (this guide). |
| CMPLX | Complex numbers, rectangular or polar. |
| STAT | Mean, standard deviation, regression: see the statistics calculator guide. |
| BASE-N | Binary, octal and hexadecimal. |
| EQN | Quadratic, cubic and simultaneous equations: see the equation solver guide. |
| MATRIX | Matrix arithmetic up to 3×3. |
| TABLE | A table of values for a function. |
| VECTOR | Vector arithmetic. |
One more key worth knowing this early: CALC. Press it to substitute a value into an expression that uses a stored variable, and SHIFT then CALC opens SOLVE, which finds an unknown numerically. That deserves its own guide: see SHIFT SOLVE on a scientific calculator.
2. Follow the order of operations
Type an expression the way you would write it on paper: powers and roots first, then multiplication and division, then addition and subtraction left to right, with brackets overriding all of it.
One case is worth knowing by name, because it trips up more than beginners: a multiplication sign you leave out. Type 6÷2(1+2) and WideMath returns 1, not 9, because the missing × between 2 and the bracket binds tighter than the ÷ in front of it, the same convention some real handhelds use. Not every calculator agrees: some read strictly left to right and would give the same key presses a different answer (see Sources).
You also rarely need to close a bracket by hand. Type 5×(3+2 and press = without ever typing the final bracket. WideMath closes it for you before solving, the same as a real handheld does.
3. Negative numbers: (-) versus the minus key
Two keys on the pad make the same short raised mark, and beginners mix them up constantly. (-) sits above the numbers and makes the next number negative: use it to start an expression, or right after a bracket or another operator. The − key sits in the numpad, next to + and ×, and subtracts one number from another.
On WideMath the two keys type the identical sign, so you cannot break a calculation by reaching for the wrong one. Build the habit anyway: your exam calculator may refuse a subtraction sign at the start of a line and demand (-) instead.
4. Fractions and the S⇔D key
WideMath keeps a fraction as a fraction. Add 0.1 and 0.2 and many calculators show 0.30000000000000004 or a rounded 0.3, because computers store decimals in binary and 0.1 cannot be written exactly in that base (see Sources). WideMath reads the same sum as three tenths and shows 3/10.
Press S⇔D to flip the displayed answer between that exact form and a decimal, and back again. The fraction key enters a simple fraction; SHIFT plus it opens a mixed number template, a whole number and fraction together, for entering something like two and a half in one go.
For adding unlike fractions and reading a mixed number back off the display, see the full guide: fractions on a scientific calculator.
5. Powers and roots
Four keys matter here. x² squares whatever you type next; SHIFT plus the same key cubes it. The power key raises a number to any power you choose; SHIFT plus it asks for a root of any index. The square root key keeps a surd exact instead of rounding it, and SHIFT plus it takes a cube root.
6. Trig and why the angle unit matters
Check the DEG pill above the keypad before you press sin, cos or tan. It cycles between Deg, Rad and Grad, and the same three letters mean a different angle depending on which one is lit. In degree mode, sin(180) is exactly 0, the way your teacher expects. Switch to radian mode without noticing, and the calculator reads that 180 as 180 radians instead, and hands back a decimal with nothing to do with the triangle you were solving.
tan(90) is the other classic trap. The tangent of a right angle is undefined, and WideMath says so plainly with Math ERROR instead of guessing a huge number.
Angle units have their own mistakes beyond this one: see degrees versus radians on a calculator.
7. Logs: log, ln and log base a
log is base 10: type log(1000) and you get 3, because 10³ is 1000. ln is the natural log, base e, the constant that shares a key with the SHIFT function above log. The separate log-base-a key opens a small template for a log in any other base: fill in the base and the value, and it divides one log by the other for you.
8. Scientific notation with ×10x
Big numbers get long fast. Instead of typing every zero, type the digits you care about, press ×10x, then the power of ten. 5×10³ is 5000 without counting a single zero by hand. The same key also takes a negative power, for a very small number just as quickly.
9. Ans and memory: STO, RCL, M+
Press = and the result is not just on screen, it is saved. Type Ans anywhere in your next expression (it has its own key, no SHIFT needed) and the calculator substitutes your last answer, saving you from re-typing a long decimal.
Memory is separate from Ans and survives even after you press AC. Press M+ to add the number on screen to memory, RCL to bring it back, and SHIFT plus RCL for STO, which overwrites memory instead of adding to it.
10. DEL versus AC
DEL removes one character, whatever sits just left of the cursor, the same job Backspace does on a keyboard. AC clears the entire line and starts over. Mixing them up is the fastest way to lose a long expression by accident: press AC out of habit to fix one wrong digit, and the other nine correct ones go with it. Use the arrow keys to reach the mistake and DEL it out instead; save AC for when you genuinely want a blank screen.
Common beginner mistakes
- Forgetting to check the angle unit. A trig answer that looks wrong is usually DEG, Rad or Grad set to the wrong one, not a broken calculator.
- Reaching for AC to fix one digit. It clears the whole line. Arrow over to the mistake and press DEL instead.
- Not knowing SHIFT and ALPHA are separate layers. A function printed above a key in another colour needs SHIFT or ALPHA first, not a second press of the same key.
- Expecting a decimal and getting a fraction or a surd. That is WideMath keeping your answer exact. Press S⇔D if you want the decimal.
- Worrying about an unclosed bracket. The calculator closes it for you on =, so a missing closing bracket is not an error here, though it still is on many handhelds.
- Skipping MODE entirely. COMP handles everyday arithmetic, but equations, matrices, statistics and base conversions each need their own mode first.
Keep practicing how to use a scientific calculator
The fastest way to learn this keypad is the way you will use it: with a real problem, not a list of button names. Redo every example here with your own numbers, then come back for the topics that need more room than one guide: fractions, SHIFT SOLVE, and the angle-unit mistakes trig brings with it, all linked above.
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Open the scientific calculator →Scientific calculator FAQ for beginners
What does the SHIFT button do on a calculator?
SHIFT unlocks the yellow function printed above each key: press SHIFT, then that key. SHIFT then the square root key types a cube root, and SHIFT then MODE opens SETUP.
What does the ALPHA key do?
ALPHA unlocks the red functions printed above each key: mostly the letters A to F plus X, Y and M, used for variables and stored memory.
How do I clear a scientific calculator?
Press DEL to remove the character just to the left of the cursor, or AC to clear the whole expression and start a fresh calculation. SHIFT then AC turns the calculator off.
Why does my calculator show a fraction instead of a decimal?
A scientific calculator can keep exact answers exact: fractions stay fractions, and square roots stay as surds unless they simplify to a whole number. Press S⇔D to see the same answer as a decimal.
Do I need a different calculator for degrees and radians?
No, the same calculator handles both. Press the DEG pill to cycle between Deg, Rad and Grad, and check it before every trig problem: sin, cos and tan give a different answer in each unit.
What is the first thing a beginner should learn on a scientific calculator?
Learn the four layers first: white number and operator keys, the yellow SHIFT layer, the red ALPHA layer, and the MODE key. Almost every other button is a combination of those four.
Sources
- Open University OpenLearn, Using a scientific calculator: getting to know your calculator, on the standard SHIFT and ALPHA keypad layout.
- Wikipedia, Order of operations, on how calculator brands disagree over implicit multiplication.
- 0.30000000000000004.com, on why 0.1 + 0.2 is not exact in binary floating point.
- math.js, the open source maths library behind WideMath's arithmetic.