Evaluate 2 + 3 × 4
- Multiplication first
- Then the addition
Answer
Typed left to right on a basic calculator this gives 20, which is the single most common calculator mistake.
Scientific calculator
Type the whole expression, get the answer as you go.
- Free
- No account
- Every step shown
- Arithmetic to calculus
Solution
Ready
Answer
Was this right?
Your recent solutions
Saved on this device only. Nothing leaves your browser.
This one is a real calculator, not a model: it parses what you type and evaluates it, so the answer is exact and instant, it works offline once the page has loaded, and nothing you enter is sent anywhere. Type a whole expression rather than pressing one key at a time — 2 + 3 * 4 answers 14, because it follows the order of operations. The solver below is for the questions a calculator cannot answer, the ones that need the working shown.
What the keys do
Everything can be typed as well as tapped. These are the ones people look for.
Powers and roots
Use ^ for a power: 2^10 is 1024. x² is the same as ^2. Use sqrt( ) for a square root and cbrt( ) for a cube root; a fractional power works too, so 8^(1/3) is 2.
Logarithms
log( ) is base 10 and ln( ) is base e. For any other base, divide: log base 2 of 32 is ln(32)/ln(2) = 5, or use log2( ).
Trigonometry
sin, cos and tan read the DEG or RAD switch under the display. asin, acos and atan give the angle back in whichever unit is selected.
Order of operations and brackets
Multiplication and division happen before addition and subtraction, and powers before both. Brackets override all of it, and 2(3+4) works without the multiplication sign.
Answer and factorial
Ans reuses the last result, so you can carry a number into the next line. n! is the factorial: 5! is 120.
Worked examples
Each one is solved the way the solver solves it: the rule first, then the line.
What is sin(30°)?
- Check the angle unit
- Read the exact value
Answer
In radians the same keystrokes give −0.988, because sin(30 radians) is a different question.
What is log base 10 of 1000?
- Ask what power of ten gives 1000
- So the logarithm is that power
Answer
What is 5 factorial?
- Multiply down to one
- Work it out
Answer
Factorials grow fast: 20! already has 19 digits, and above 170! the answer is larger than a computer double can hold.
Where marks get lost
Leaving it in the wrong angle unit
Degrees and radians give completely different answers for the same keystrokes. The DEG/RAD switch sits under the display, and it is the first thing to check when a trig answer looks wrong.
Trusting left-to-right
A calculator that evaluates as you type gives 2 + 3 × 4 = 20. One that follows the order of operations gives 14. This one gives 14, which is the mathematically correct answer.
Losing a bracket in a fraction
Typing 1/2+3 gives 3.5, not 0.2. A fraction with anything more than one term underneath needs brackets: 1/(2+3).
Questions
How do I use a scientific calculator?
Type the expression the way it is written, including brackets, and read the answer underneath. It updates as you type, so you can see a mistake before you finish rather than after.
What is a scientific calculator used for?
Anything beyond the four basic operations: powers, roots, logarithms, trigonometry, factorials and scientific notation. It is the calculator assumed by most algebra, trigonometry, physics and chemistry courses.
How do I do exponents on a calculator?
Use the ^ key, or type it: 2^10 is 1024. For a square, ^2 is enough. A negative or fractional exponent works the same way, so 2^-3 is 0.125 and 8^(1/3) is 2.
How do I do a square root?
Use sqrt( ) around the number: sqrt(16) is 4. For any other root, use a fractional power — the fifth root of 32 is 32^(1/5) = 2.
How do I do log on a calculator?
log( ) is base 10 and ln( ) is the natural log, base e. For another base, divide two logs: log base 2 of 32 is ln(32)/ln(2) = 5.
Should I use degrees or radians?
Degrees for geometry and most school trigonometry, radians for calculus and anything involving rates of change. The switch under the display shows which is active, and it changes every trig answer.
What is the difference between a scientific and a graphing calculator?
A scientific calculator evaluates expressions and returns a number. A graphing calculator also draws the function, so you can see where it crosses and turns. For a single value, a scientific calculator is faster.
Does it follow the order of operations?
Yes. Powers first, then multiplication and division, then addition and subtraction, with brackets overriding all of it. 2 + 3 × 4 is 14 here, not 20.
Is anything I type sent anywhere?
No. The calculator parses and evaluates entirely in your browser, so it keeps working with the network off and nothing you enter leaves the page.