How to Use the Basic Calculator
Our Basic Calculator is a simple four-function calculator for everyday arithmetic: addition, subtraction, multiplication and division, with memory functions and percentage. Click into the calculator and type on your keyboard, or use the on-screen buttons — both work interchangeably.
Buttons and What They Do
| Button | What it does |
|---|---|
| AC | Clears the current calculation completely (does not clear memory) |
| ← (Backspace) | Removes the last digit you typed |
| % | Calculates a percentage based on the current calculation, or divides the displayed number by 100 when used on its own (see below) |
| +/− | Switches the current number between positive and negative |
| MC | Clears the memory back to zero |
| MR | Recalls the number stored in memory to the display |
| M+ | Adds the displayed number to memory |
| M− | Subtracts the displayed number from memory |
How the Percentage Button Works
The % button behaves differently depending on whether you’re in the middle of a calculation. If you’ve entered a number, an operator, and then a second number before pressing %, it works out that percentage of the first number — for example, 200 + 10% calculates 10% of 200 (which is 20) and adds it, giving 220. If you press % on its own with no pending operator, it simply divides the displayed number by 100 — for example, 50% becomes 0.5.
How Calculations Are Chained
Like most simple calculators, this tool works step by step rather than following full mathematical order of operations. Pressing an operator immediately after another (with a number in between) calculates the result so far before continuing. For example, entering 2 + 3 × 4 calculates 2 + 3 = 5 first, then 5 × 4 = 20 — it doesn’t apply multiplication before addition the way a scientific calculator or spreadsheet formula would. If you need standard mathematical order of operations, use a scientific calculator instead.
Keyboard Shortcuts
- 0–9 — enter digits
- + − * or x / — addition, subtraction, multiplication, division
- Enter or = — calculate the result
- Backspace — delete the last digit
- Esc — clear everything (AC)
- % — percentage
Frequently Asked Questions
What’s the difference between AC and the backspace button?
AC clears the entire calculation, including any number stored for a pending operation, and resets the display to zero. The backspace button (←) only removes the last digit you typed, letting you correct a typo without starting over.
Does clearing the calculator also clear the memory?
No. Pressing AC or making a new calculation does not affect the memory value. Memory is only cleared when you press MC, so you can keep a running total in memory across several separate calculations.
How does the percentage button work?
If you’ve already entered a number, an operator and a second number, pressing % calculates that percentage of the first number (so 200 + 10% adds 20, giving 220). Used on its own, % simply divides the current number by 100.
Does this calculator follow order of operations (BODMAS/PEMDAS)?
No. Like most basic four-function calculators, it calculates step by step in the order you press the buttons, rather than applying multiplication and division before addition and subtraction. For calculations that need standard mathematical order of operations, a scientific calculator or spreadsheet is more appropriate.
What happens if I divide by zero?
The display shows “Error” and further operators and digits are ignored until you press AC to clear the calculation. This avoids showing a meaningless or undefined result.
Can I use my keyboard instead of clicking the buttons?
Yes. Click anywhere on the calculator first to focus it, then use number keys, +, -, * or x, /, Enter or = to calculate, Backspace to delete a digit, Esc to clear everything, and % for percentage.