Question 1

Does the calculator follow the order of operations?

Accepted Answer

Yes. The calculator evaluates the whole input according to mathematical rules: brackets first, then powers, then multiplication and division, and finally addition and subtraction. 2 + 3 × 4 therefore gives 14, not 20. If you want to add first, use brackets: (2 + 3) × 4 = 20. Powers are evaluated from right to left, so 2^3^2 is 2^9 = 512.

Question 2

How do I calculate percentages on the calculator?

Accepted Answer

The % key works like on a classic desk calculator: 200 + 10% gives 220 (mark-up), 200 − 10% gives 180 (discount) and 200 × 10% gives 20 (the percentage amount). A number on its own with % is divided by 100, so 50% is 0.5. For base value, percentage rate or percentage change, our percentage calculator shows every variant with the working.

Question 3

Why does 0.1 + 0.2 give exactly 0.3 here?

Accepted Answer

Computers store decimal numbers in binary, where 0.1 cannot be represented exactly. Without correction the result would be 0.30000000000000004. Our calculator rounds every result to 12 significant digits and sets tiny leftovers from subtractions to zero. So you see 0.3 — just like on a good desk calculator. For everyday use, school and work this precision is more than sufficient.

Question 4

What do DEG and RAD mean?

Accepted Answer

DEG stands for degrees (a full circle is 360°), RAD for radians (a full circle is 2π). The angle mode determines how sin, cos and tan interpret their argument. In DEG mode sin(30) = 0.5; in RAD mode sin(30) is about −0.988, because 30 is read as radians. School and trades mostly use degrees, physics and higher mathematics often use radians.

Question 5

Can I use the calculator with my keyboard?

Accepted Answer

Yes, completely. Type digits and the characters + − * / ^ ( ) directly, and a comma or point for decimals. Enter or = calculates the result, Backspace deletes the last input, Esc clears everything. Shortcuts exist for functions: s, c and t for sin, cos and tan, r for the square root, l for ln, g for log and p for π. You can also paste a calculation from the clipboard.

Question 6

How do the memory keys M+, M−, MR and MC work?

Accepted Answer

The memory holds a number while you keep calculating. M+ adds the current result to the memory, M− subtracts it, MR inserts the memory value into the calculation and MC clears the memory. Typical example: you calculate several items of a shopping list one after another, press M+ each time and recall the total with MR at the end.

Question 7

What happens when dividing by zero?

Accepted Answer

Division by zero is mathematically undefined. The calculator then shows the note "Division by zero is undefined" instead of returning a wrong number. It reacts in the same way to other invalid inputs such as the square root of a negative number, the logarithm of zero or tan(90°). Your input is kept so that you can correct it.

Question 8

Are my calculations stored or transmitted?

Accepted Answer

No. All calculations run exclusively in your browser, nothing is sent to a server. The history of the last 20 calculations is kept only in your browser's local storage and can be deleted at any time with "Clear history". The current calculation also appears in the address bar so that you can share it as a link.

Guide: Online Calculator

Using an Online Calculator Properly: Rules, Functions and Common Mistakes

Order of Operations: The Rules and How a Calculator Applies Them

Percent on a Calculator: How the % Key Works

Scientific Calculator: sin, cos, tan, ln and log Explained

Calculating Roots and Powers: Using x², xʸ and √ Correctly

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