How do I use a scientific calculator?
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Short answer
Enter the calculation the way it's written, use parentheses for grouping, and press equals. Before any trig, check the angle mode: sin(30) gives 0.5 in degrees but about −0.988 in radians, which is the most common wrong answer. Know the main keys as well: log is base 10, ln is base e, and EXP enters powers of ten.
What do the main keys do?
- sin, cos, tan: trigonometry functions, with results depending on the angle mode.
- sin⁻¹, cos⁻¹, tan⁻¹: find the angle from a ratio.
- log: base 10 logarithm. log(1000) = 3.
- ln: natural logarithm, base e. ln(1000) is about 6.908.
- xʸ or ^: raise a number to a power.
- EXP or EE: enter scientific notation. 3 EXP 8 means 3 × 10⁸.
- n!: factorial. 5! = 120.
- Ans: reuse your last result.
- M+, M−, MR: add to, subtract from, and recall a stored number.
What order does a scientific calculator work in?
Most follow the standard order: parentheses, exponents, multiplication and division from left to right, then addition and subtraction from left to right. So 6 ÷ 2 × 3 = 9, not 1.
Negative numbers are the classic trap. Most calculators read −3² as −(3²) = −9, while (−3)² = 9. When in doubt, add parentheses around it.
How can I practice on a free one?
Try this scientific calculator, which has Deg and Rad keys, logs, factorials and memory. Your keyboard works too, and an operator after a result carries it forward, so 12 × 3 = followed by + 4 = gives 40.
On an iPhone, open Calculator, tap the mode button and choose Scientific. It uses degrees by default, and Rad switches to radians.
Can I use a calculator on the SAT?
Yes, for the Math section. College Board's SAT calculator policy covers the Desmos calculator built into its testing app and which handheld models are allowed. Check that page before test day, as models with features such as a computer algebra system are banned.